#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <math.h>
#include <map>
#include <set> 
#include <queue>
#define int long long

using namespace std;

typedef pair<int, int> PII;

const int N = 1e6 + 10, mod = 1e9 + 7;

int n, m, k;
int g[N], h[N];
int ans;
void solve() 
{
    cin >> n;
    string s;
    cin >> s;
    s = " " + s;
    for(int i = 1; i <= n; i++)
    {
        g[i] = g[i - 1];
        h[i] = h[i - 1];
        if(s[i] == 'G') g[i] ++;
        else h[i] ++;
    }

    multiset<int> gs, hs;
    multiset<int> acnt, bcnt; // 需要考虑重合问题 
    for(int i = 1; i <= n; i++)
    {
        int x;
        cin >> x;

        if(s[i] == 'G')
        {
            if(g[x] - g[i - 1] == g[n]) // 这个可以是答案
            {
                //情况2
                auto it = hs.lower_bound(i);
                int d = distance(it, hs.end());
                auto it2 = bcnt.lower_bound(i);
                int D = distance(it2, bcnt.end());
                ans += d - D;
                acnt.insert(x);
            }
            gs.insert(x);

        }
        else
        {
            if(h[x] - h[i - 1] == h[n])
            {
                auto it = gs.lower_bound(i);
                int d = distance(it, gs.end());
                auto it2 = acnt.lower_bound(i);
                int D = distance(it2, acnt.end());
                ans += d - D;
                bcnt.insert(x);
            }
            hs.insert(x);
        }
    }
    cout << ans + acnt.size() * bcnt.size() << endl; // 最后加上情况1
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int T = 1;
    // cin >> T;
    while (T--) 
    {
        solve();
    }
    return 0;
}