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#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <set>
#include <algorithm>
using namespace std;

#define MAXN 1000007
#define MAXM 1000007

//#define DEBUGPRINT
//#define DEBUGPRINT2
//#define DEBUGASSERT

#ifdef DEBUGPRINT
#define DEBPRINT(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBPRINT(...)
#endif
#ifdef DEBUGPRINT2
#define DEBPRINT2(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBPRINT2(...)
#endif
#ifdef DEBUGASSERT
#define ASSERT(x) assert(x)
#else
#define ASSERT(x)
#endif

typedef long long slng;

struct player {
	int money;
	int idx;
	int nr;
	int used;
} p[MAXN];
bool operator<(const player &lhs, const player &rhs) {
	/* Ones with equal nr should be equal, and should be inserted with equal money. */
	if (lhs.money != rhs.money)
		return lhs.money < rhs.money;
	return lhs.nr < rhs.nr;
}

slng N, M;
int money[MAXN];
char automat[MAXM];
slng ret = -1;

slng solve(int startp) {
	set<player> cykl;
	set<player>::iterator minp;
	player pl;
	int i, a, delta, fulldelta, mindelta, cykllen;
	slng numcykl;
	slng ret = -1;
	
	DEBPRINT2("---------------------------------\n");
	// first round
	DEBPRINT("Adding: money=%d idx=%d nr=%d\n", p[startp].money, p[startp].idx, p[startp].nr);
	cykl.insert(p[startp]);
	p[startp].used = 1; // reset
	p[startp].money += automat[startp];
	delta = mindelta = automat[startp];
	for (i = 0, a = (startp + N) % M; a != startp; i++, a = (a + N) % M) {
		minp = cykl.begin();
		DEBPRINT("[i=%d a=%d delta=%d]\n", i, a, delta);
		DEBPRINT("minp.money=%d minp.idx=%d minp.nr=%d\n", (*minp).money, (*minp).idx, (*minp).nr);
		while (minp != cykl.end() && (*minp).money + delta <= 0) {
			slng retcand = N * (i - (*minp).idx) + (*minp).nr;
			DEBPRINT("(%d %lld)\n", (*minp).nr, retcand);
			if (ret == -1 || retcand < ret) {
				DEBPRINT2("CANDIDATE_A: i=%d minp.money=%d minp.idx=%d minp.nr=%d delta=%d | retcand=%lld\n", i, (*minp).money, (*minp).idx, (*minp).nr, delta, retcand);
				ret = retcand;
			}
			minp++;
			DEBPRINT(" minp.money=%d minp.idx=%d minp.nr=%d\n", (*minp).money, (*minp).idx, (*minp).nr);
			cykl.erase(cykl.begin());
		}
		pl = p[a % N];
		pl.idx = i+1;
		pl.money -= delta;
		DEBPRINT("Adding: money=%d idx=%d nr=%d\n", pl.money, pl.idx, pl.nr);
		cykl.insert(pl);
		p[a % N].used = 1; // reset;
		p[a % N].money += automat[a];
		delta += automat[a];
		if (delta < mindelta)
			mindelta = delta;
	}
	fulldelta = delta;
	cykllen = i+1;
	DEBPRINT2("<fulldelta=%d cykllen=%d>\n", fulldelta, cykllen);
	ASSERT(a == startp);
	
	numcykl = 0;
	if (fulldelta < 0) {
		minp = cykl.begin();
		ASSERT(minp != cykl.end());
		
		DEBPRINT2("> %d, fulldelta=%d, mindelta=%d\n", (*minp).money + delta + mindelta, fulldelta, mindelta);
		if ((*minp).money + delta + mindelta > 0) {
			numcykl = ((*minp).money + delta + mindelta - 1) / (-fulldelta) + 1;
			delta += numcykl * fulldelta;
		}
		DEBPRINT2("> %d, numcykl=%lld\n", (*minp).money + delta + mindelta, numcykl);
		ASSERT((*minp).money + delta + mindelta <= 0);
	}
	DEBPRINT2("<fulldelta=%d cykllen=%d numcykl=%d>\n", fulldelta, cykllen, numcykl);
	
	// last round
	for (a = startp; ; i++, a = (a + N) % M) {
		minp = cykl.begin();
		DEBPRINT("{i=%d, a=%d delta=%d}\n", i, a, delta);
		DEBPRINT("minp.money=%d minp.idx=%d minp.nr=%d\n", (*minp).money, (*minp).idx, (*minp).nr);
		while (minp != cykl.end() && (*minp).money + delta <= 0) {
			slng retcand = N * (numcykl * cykllen + i - (*minp).idx) + (*minp).nr;
			DEBPRINT("(%d %lld)\n", (*minp).nr, retcand);
			if (ret == -1 || retcand < ret) {
				DEBPRINT2("CANDIDATE_B: i=%d minp.money=%d minp.idx=%d minp.nr=%d delta=%d | retcand=%lld\n", i, (*minp).money, (*minp).idx, (*minp).nr, delta, retcand);
				ret = retcand;
			}
			minp++;
			cykl.erase(cykl.begin());
		}
		delta += automat[a];
		if ((a + N) % M == startp) {
			i++;
			break;
		}
	}
	// one more round to make everyone really make a round.
	for (a = startp; ;i++, a = (a + N) % M) {
		minp = cykl.begin();
		DEBPRINT("{i=%d, a=%d delta=%d}\n", i, a, delta);
		DEBPRINT("minp.money=%d minp.idx=%d minp.nr=%d\n", (*minp).money, (*minp).idx, (*minp).nr);
		while (minp != cykl.end() && (*minp).money + delta <= 0) {
			slng retcand = N * (numcykl * cykllen + i - (*minp).idx) + (*minp).nr;
			DEBPRINT("(%d %lld)\n", (*minp).nr, retcand);
			if (ret == -1 || retcand < ret) {
				DEBPRINT2("CANDIDATE_C: minp.money=%d minp.idx=%d minp.nr=%d | retcand=%lld\n", (*minp).money, (*minp).idx, (*minp).nr, retcand);
				ret = retcand;
			}
			minp++;
			cykl.erase(cykl.begin());
		}
		delta += automat[a];
		if ((a + N) % M == startp) {
			i++;
			break;
		}
	}
	
	return ret;
}

int main() {
	int i;
	slng ret = -1;
	
	scanf("%lld", &N);
	for (i = 0; i < N; i++) {
		scanf("%d", &p[i].money);
		p[i].nr = i+1;
	}
	scanf("%lld", &M);
	scanf("%s", automat);
	ASSERT(strlen(automat) == M);
	for (i = 0; i < M; i++) {
		if (automat[i] == 'W')
			automat[i] = +1;
		else
			automat[i] = -1;
	}
	if (N > M) {
		for (i = M; i < N; i++) {
			if (p[i].money < p[i % M].money)
				p[i % M] = p[i];
		}
	}
	DEBPRINT2("N=%lld M=%lld\n", N, M);
	
	for (i = 0; i < min(M, N); i++) {
		if (p[i].used == 0) {
			slng retcand = solve(i);
			DEBPRINT2("%lld\n", retcand);
			if (retcand != -1 && (ret == -1 || retcand < ret)) {
				ret = retcand;
			}
		}
	}
	printf("%lld\n", ret);
	
	return 0;
}