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
#include <algorithm>
#include <cstdio>
#include <vector>
using namespace std;
typedef long long ll;

typedef pair<int,int> pii;

const int N_MAX = 1e6+10;
const int M_MAX = 1e6+10;

int n, c[N_MAX], m;
char a[M_MAX];
vector<vector<int>> cycles;
int cycle[N_MAX];
bool cycle_used[M_MAX];
int cycle_pos[M_MAX];

void build_cycle() {
  for (int i = 0; i < n; i++) {
    int p = i % m;
    if (cycle_used[p]) {
      cycle[i] = cycle[p];
    } else {
      cycle[i] = cycles.size();
      vector<int> new_cycle;
      int pos = 0;
      do {
        new_cycle.push_back(p);
        cycle[p % n] = cycle[i];
        cycle_pos[p] = pos;
        cycle_used[p] = true;
        p = (p + n) % m;
        pos++;
      } while (p != (i % m));
      cycles.push_back(new_cycle);
    }
  }

//  for (int i = 0; i < n; i++) {
//    printf("%c [cycle=%d, start=%d]\n", 'A'+i, cycle[i], cycle_pos[i % m]);
//  }
//  for (auto c : cycles) {
//    printf("cycle=");
//    for (auto x : c) printf("%d ", x);
//    printf("\n");
//  }
}

void double_cycle() {
  for (auto& cc : cycles) {
    int k = cc.size();
    for (int i = 0; i < k; i++) cc.push_back(cc[i]);
  }
}

ll lost_slow(int p) {

}

ll lost(int p) {
  vector<int>& cc = cycles[cycle[p]];
  int h = c[p];

  ll t; int i;
  for (t = (p+1), i = cycle_pos[p % m]; t < 1000000; t += n, i = (i+1) % cc.size()) {
    h += (a[cc[i]] == 'W' ? 1 : -1);
    if (h == 0) {
      return t;
    }
  }
  return -1;
}

int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", c+i);
  scanf("%d", &m);
  scanf("%s", a);

  build_cycle();

  ll ans = -1;

  for (int i = 0; i < n; i++) {
    ll res = lost(i);
    // printf("lost(%d) %lld\n", i, res); 
    // res = lost_slow(i);
    // printf("lost(%d) %lld\n", i, res);
    
    if (res != -1) {
      ans = (ans == -1) ? res : min(ans, res);
    }
  }

  printf("%lld\n", ans);
  return 0;
}