1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
#include <stdio.h>

#define BUF_READ 10000000
#define BUF_BORDER 100
#define BUF_SIZE (BUF_READ+BUF_BORDER+1)

char buf[BUF_SIZE];
char *buf_cur;
char *buf_end;
int file_finished;

void buf_init()
{
        int bytes_read;
        
        bytes_read = fread( buf, 1, BUF_READ, stdin );
        buf_cur = buf;
        buf_end = buf + bytes_read;
        if (bytes_read < BUF_READ) {
                file_finished = 1;
        } else {
                file_finished = 0;
        }
}

void buf_findNextNumber()
{
        while ( *buf_cur < '0' || *buf_cur > '9') {
                buf_cur++;
        }
}

void read_buffer_if_needed(int border)
{
        int i, d, bytes_read;

        if (file_finished == 1) {
                return;
        }

        d = buf_end - buf_cur;
        if (d > border) {
                return;
        }

        for(i = 0; i < d; ++i) {
                buf[i] = buf_cur[i];
        }

        bytes_read = fread( buf+d, 1, BUF_READ, stdin );
        if (bytes_read < BUF_READ) {
                file_finished = 1;
        }
        buf_cur = buf;
        buf_end = buf+d+bytes_read;

}

int buf_getNextNumber()
{
        int number = 0;

        read_buffer_if_needed(BUF_BORDER);

        buf_findNextNumber();
        number = *buf_cur - '0';
        buf_cur++;
        while( *buf_cur >= '0' && *buf_cur <= '9') {
                number = number*10 + *buf_cur - '0';
                buf_cur++;
        }
        return number;        
}

void buf_find_PW()
{
        read_buffer_if_needed(1000020);

        while( *buf_cur != 'W' && *buf_cur != 'P' ) {
                buf_cur++;
        }
}

#define MAX_N 1000000
#define MAX_M 1000000

#define MIN(a,b) (((a)<(b))?(a):(b))

int n, m;
int s[MAX_N];
int c[MAX_M];
int sumc;
int cycle;

int wc[MAX_N];
int minc[MAX_N];
int movec[MAX_N];

int losers[MAX_N];

int nwd(int a,int b)
{
        int c;
        while(b != 0) {
                c = a % b;
                a = b;
                b = c;
        }
        return a;
}

void calc_wc()
{
        int i, j;
        int min;

        min = MIN(n, m);
        for(i = 0; i < min; ++i) {
                wc[i] = c[i % m];
                minc[i] = wc[i];
                movec[i] = 0;
                for(j = 1; j < cycle; j++) {
                        wc[i] += c[ (j*n + i) % m];
                        if (wc[i] < minc[i]) {
                                minc[i] = wc[i];
                                movec[i] = j;
                        }
                }
        }

        if (min < n) {
                for(i = min; i < n; ++i) {
                        wc[i] = wc[i % min];
                        minc[i] = minc[i % min];
                        movec[i] = movec[i % min];
                }
        }
}

int none_loose()
{
        int i;
        int result = 1;

        for(i = 0; i < n; ++i) {
                if (wc[i] < 0) {
                        result = 0;
                        break;
                }
                if (minc[i] + s[i] <= 0) {
                        result = 0;
                        break;
                }
        }
        return result;
}

int lose_step_min;
int loser_min;
int losers_num;

int lose_cycles[MAX_N];
int min_lose_cycle;


int loose_in_first_cycle()
{
        int i;
        
        losers_num = 0;
        for(i = 0; i < n; ++i) {
                if (minc[i] + s[i] <= 0) {
                        losers[losers_num] = i;
                        losers_num++;
                }
        }
        return losers_num;
}


void calc_loose_cycles()
{
        int i;

        for(i = 0; i < n; ++i) {
                if (wc[i] >= 0) {
                        lose_cycles[i] = -1;
                        continue;
                }
                lose_cycles[i] = (s[i]+minc[i])/(-wc[i]);
                if ((s[i]+minc[i]) % (-wc[i]) != 0) {
                        lose_cycles[i]++;
                }
//              printf("lc (%d) = (%d)\n", i, lose_cycles[i]);
        }
}

void find_losers()
{
        int i;

        min_lose_cycle=MAX_M+1;
        losers_num = 0;
        for(i = 0; i < n; ++i) {
                if (wc[i] >= 0) {
                        continue;
                }
                if (min_lose_cycle > lose_cycles[i]) {
                        min_lose_cycle = lose_cycles[i];
                        losers_num = 0;
                }
                if (min_lose_cycle == lose_cycles[i]) {
                        losers[losers_num++] = i;
                }
        }
//        printf("min lose c %d\n", losers_num);
}

void find_first_loser()
{
        int i, j;
        int cur_looser;
        int money;

        lose_step_min = MAX_M+1;
        for(i = 0; i < losers_num; ++i) {
                cur_looser = losers[i];
                money = s[cur_looser];
                for(j = 0; j < cycle; j++) {
                        money += c[ (j*n + cur_looser) % m];
                        if (money == 0) {
                                if (j < lose_step_min) {
                                        lose_step_min = j;
                                        loser_min = cur_looser;
                                        break;
                                }
                        }
                }
        }
}

void find_first_loser2()
{
        int i, j;
        int cur_looser;
        int money;

        lose_step_min = MAX_M+1;
        for(i = 0; i < losers_num; ++i) {
                cur_looser = losers[i];
                money = s[cur_looser] + wc[cur_looser]*min_lose_cycle;
                for(j = 0; j < cycle; j++) {
                        money += c[ (j*n + cur_looser) % m];
                        if (money == 0) {
                                if (j < lose_step_min) {
                                        lose_step_min = j;
                                        loser_min = cur_looser;
                                        break;
                                }
//                                printf("money = 0\n");
                        }
                }
        }
}


int main()
{
        int i;
        //int l_cycle;
        int losers_num;
        long long result;

        buf_init();
        
        n = buf_getNextNumber();
        for(i = 0; i < n; ++i) {
                s[i] = buf_getNextNumber();
        }

        m = buf_getNextNumber();

        buf_find_PW();

        sumc = 0;
        for(i = 0; i < m; ++i) {
                if (*buf_cur == 'W') {
                        c[i] = 1;
                        sumc++;
                } else {
                        c[i] = -1;
                        sumc--;
                }
                buf_cur++;
        }

//      printf("n = %d, m = %d\n", n, m);
//      for(i = 0; i < n; ++i) {
//              printf(" %d", s[i]);
//      }
//      printf("\n");

//      for(i = 0; i < m; ++i) {
//              printf(" %d", c[i]);
//      }
//      printf("\n");

        if (sumc == m) {
                printf("-1\n");
                return 0;
        }

        cycle = m / nwd(n, m);
//      printf("cycle %d\n", cycle);

        calc_wc();

//      for(i = 0; i < n; ++i) {
//              printf("i=(%d), wc=(%d), min=(%d), idx=(%d)\n", i, wc[i], minc[i], movec[i]);
//      }

        if (none_loose() == 1) {
                printf("-1\n");
                return 0;
        }

        if ((losers_num = loose_in_first_cycle()) > 0) {
//              printf("losers_num in first_cycle (%d)\n", losers_num);
                find_first_loser();
//              printf("loser=(%d), lose_step (%d)\n", loser_min, lose_step_min);
              printf("%d\n", lose_step_min * n + loser_min + 1);
                return 0;
        }

        calc_loose_cycles();
        find_losers(); 
        find_first_loser2();

//      printf("losers_num in (%d) cycle (%d)\n", min_lose_cycle, losers_num);
//      printf("loser=(%d), lose_step (%d)\n", loser_min, lose_step_min);
//
        result = ((long long) min_lose_cycle) * ((long long) cycle) * ((long long) n) 
               + ((long long) lose_step_min) * ((long long) n) + loser_min + 1;


        printf("%lld\n", result);


        return 0;
}