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#include<iostream>
#include<cstdio>
#include<vector>
#include<deque>
#include<algorithm>
#include<limits>

using namespace std;

typedef long long ll;

const ll infty = numeric_limits<long long>::max();
const int NM=1000000;
int a[NM];
int cycles[NM];
ll howMany[NM];
int n_cycles;
int cycle_len;
int n,m;

struct elem {
    vector<int> buddies;
    int delta; // +1 or -1
    elem() {}
} cycle[NM];

int nwd(int a, int b) { return b ? nwd(b, a % b) : a; }

void getCycle(int a) {
    for(int i=0; i<cycle_len; ++i) {
        cycle[i].delta=cycles[a];
        cycle[i].buddies.clear();
        while(a < n)
        {
            cycle[i].buddies.push_back(a);
            a += m;
        }
        a= (a+n) % m;
    }
}

ll findDrop(int b, int d, int l) {
    if((b-d) % (-l) == 0) return (b-d)/(-l);
    return (b-d)/(-l) +1;
}

void processCycle() {
    deque<int> drops;
    int level=0;
    for(int i=0; i<cycle_len; ++i) {
        level+=cycle[i].delta;
        if(-level > (int)drops.size())
            drops.push_back(i);
    }
    int first=0;
    int last=cycle_len-1;
//    cout << "["<<first << "," << last << "]" << endl;
//    cout << "initial drops" << endl;
//    for(int i=0; i<drops.size(); ++i) cout << drops[i] << " " ;
//    cout << endl;

    int curr_pos=0;
    for(int i=cycle_len-1; i>=0; --i) {
//        cout << "curr_poss " << curr_pos << ": " << cycle[curr_pos].buddies.size() << endl;
        for(auto bud : cycle[curr_pos].buddies) {
            int budget=a[bud];
            // czy mozna zejsc do -budget ? :
//            cout << "dropsize=" << drops.size() << " budget=" << budget << endl;
            if(drops.size() >= budget) {
                howMany[bud]=drops[budget-1]-first+1;
//                cout << bud << ": " << howMany[bud] << endl;
                continue;
            }
            // nie mozna zejsc do -budget ale suma cyklu jest ujemna:
            if(level < 0) {
                // znajdz min k t.ze. budget - k(-level) <= drops.size
                ll k=findDrop(budget,drops.size(),level);
                howMany[bud]=k*cycle_len+(drops[budget-k*(-level)-1]-first+1);
//                cout << bud << ": drop : " << k << ","  << howMany[bud] << endl;
                continue;
            }
            // ten koles nie ma szans stracic calej kasy:
            howMany[bud]=infty;
//            cout << bud << ": " << howMany[bud] << endl;
        }

        --first; --last;
        if(cycle[i].delta == -1)
            drops.push_front(first);
        else if (!drops.empty()) drops.pop_front();
        if(!drops.empty() && drops.back() > last) drops.pop_back();
   //     cout << "drops next: ";
   //     for(int i=0; i<drops.size(); ++i) cout << drops[i] << " ";
   //     cout << endl;
        curr_pos=i;
    }
}

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

    scanf("%d",&m);
    {
        char buf[NM + 4];
        scanf("%s", buf);
        for(int i=0; i < m; ++i)
            cycles[i] = buf[i] =='W' ? 1 : -1;
    }

    //cout << "n= " << n << endl;
    //for(int i=0; i<n; ++i) cout << a[i] << " ";
    //cout << endl;

    //cout << "m= " << m << endl;
    //for(int i=0; i<m; ++i) cout << cycles[i] << " ";
    //cout << endl;

    n_cycles=nwd(m,n); cycle_len=m/n_cycles;

    for(int i=0; i<nwd(n,m); ++i) {
       getCycle(i);  // w cycle laduje odpowiedni cykl
   // cout << "Cykl " << i << endl;
   //    for(int i=0; i<cycle_len; ++i) {
   //      cout << i << ": " << cycle[i].delta << endl;
   //      cout << "buddies: ";
   //      for(auto bud : cycle[i].buddies) cout << bud << ",";
   //    cout << endl;
   // }
       processCycle(); // wylicza ile razy zagra koles z tego cyklu zanim zbankrutuje
    }

    // wynik: i=argmin(howMany), wynik=i+(min(howMany)*(n-1))
    ll result=infty;
    for(int i=0; i<n; ++i)
        if(howMany[i] < infty)
            if(result > (howMany[i]-1)*n+i+1) result=(howMany[i]-1)*n+i+1;
    if(result==infty) printf("%d\n",-1);
    else printf("%lld\n",result);
    return 0;
}