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#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
#include <cassert>
#include <cstring>
#include <ext/numeric>
#include <list>
using namespace std ;
using namespace __gnu_cxx ;
typedef long long LL ;
typedef pair<int,int> PII ;
typedef vector<int> VI ;
const int INF = 1e9+100 ;
const LL INFLL = (LL)INF * (LL)INF ;
#define REP(i,n) for(i=0;i<(n);++i)
#define ALL(c) c.begin(),c.end()
#define VAR(v,i) __typeof(i) v=(i)
#define FOREACH(i,c) for(VAR(i,(c).begin());i!=(c).end();++i)
#define CLEAR(t) memset(t,0,sizeof(t))
#define PB push_back
#define MP make_pair
#define FI first
#define SE second

template<class T1,class T2> ostream& operator<<(ostream &s, const pair<T1,T2> &x) { s<< "(" << x.FI << "," << x.SE << ")"; return s;}
template<class T>           ostream& operator<<(ostream &s, const vector<T>   &t) { FOREACH(it, t) s << *it << " " ; return s ; }
template<class T>           ostream& operator<<(ostream &s, const set<T>      &t) { FOREACH(it, t) s << *it << " " ; return s ; }
template<class T1,class T2> ostream& operator<<(ostream &s, const map<T1, T2> &t) { FOREACH(it, t) s << *it << " " ; return s ; }

///////////////////////////////////////////

// struktura sledzaca minimum w przesuwajacym sie oknie
template<class T>
class WindowMin {
	deque<T> t ;
public:
	void insert(T a) {
		while(!t.empty() && t.back() > a) t.pop_back() ;
		t.PB(a) ;
	}
	void remove(T a) {
		if(t.front()==a) t.pop_front() ;
	}
	T getMin() {
		return t.front() ;
	}
	void clear() {
		t.clear() ;
	}
} ;
//////////////////////////////////////////

int ceil(int a, int b) {
//	assert(a>=0 && b>0) ;
	return (a+b-1)/b ;
}

const int MAXN = 1000100 ;

int h[MAXN] ;
short autom[MAXN] ;
bool used[MAXN] ;

typedef queue<int, list<int> > QUEUE ;
QUEUE __where[4*MAXN+1] ;
QUEUE *where = &__where[2*MAXN] ;

int main()
{
	ios_base::sync_with_stdio(0) ;
	int n, m, i, j ;
	char c ;
	cin >> n ;
	REP(i, n) cin >> h[i] ;
	cin >> m ;
	REP(i, m) {
		cin >> c ;
		if(c=='W') autom[i] = 1 ;
		else if(c=='P') autom[i] = -1 ;
//		else assert(false) ;
	}
	
	const int move = n%m ;
	LL ret=INFLL ;
	VI cycle, s ;
	WindowMin<int> window ;
	
	REP(i, m) {
		if(used[i]) continue ;
		cycle.clear() ;
		s.clear() ;
		window.clear() ;
		j=i ;
		do {
			cycle.PB(j) ;
			used[j]=true ;
			j = (j+move)%m ;
		} while(!used[j]) ;
		
		const int len = cycle.size() ;
		for(j=-2*len ; j<=2*len ; j++)		// czyszczenie
			where[j] = QUEUE() ;
		
		int sum=0 ;
		s.PB(0) ;
		REP(j, len) {
			sum += autom[cycle[j]] ;
			s.PB(sum) ;
			where[sum].push(j+1) ;
			window.insert(sum) ;
		}
		for(j=1 ; j<=len ; j++) {
			const int a = cycle[j-1] ;
			for(int b=a ; b<n ; b+=m) {
				int H=h[b] ;
				const int _min = window.getMin()-s[j-1] ;
				
				if(sum>=0 && H+_min>0) continue ;
				LL act_ret=b+1 ;	// tyle ruchow trzeba by do niego dojsc i dostac pierwsze losowanie
				if(sum<0 && H+_min>0) {
					LL k = ceil(H+_min, -sum) ; // tyle pelnych cyklow mozemy uzyc
					act_ret += k*len*n ;
					H += k*sum ;
				}
//				assert(H+_min<=0) ;
				
//				assert(!where[-H+s[j-1]].empty()) ;
				const int l = where[-H+s[j-1]].front() ;
//				assert(l>=j) ;
//				assert(l-j<len) ;
				act_ret += (LL)(l-j)*n ;
				ret = min(ret, act_ret) ;
			}
			
			window.remove(s[j]) ;
//			assert(!where[s[j]].empty() && where[s[j]].front()==j) ;
			where[s[j]].pop() ;
				
			window.insert(sum+s[j]) ;
			where[sum+s[j]].push(len+j) ;
		}
	}
	if(ret==INFLL) cout << -1 << endl ;
	else cout << ret << endl ;
}