E

#include <bits/stdc++.h>
using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define ff     first
#define ss     second
#define pb     push_back

int main()
{
    int n;
    cin>>n;

    vector<int> a(n);
    for(auto &e: a)     cin>>e;

    string s;
    cin>>s;

    ll int ans = 0;

    // mex = 1
    {
        ll int cntM0=0;
        ll int cntX0=0;
        ll int cntM1=0;
        ll int cntX1=0;
        ll int cntM2=0;
        ll int cntX2=0;

        for(int i=0; i<n; i++)
        {
            cntX0 += (s[i]=='X' && a[i]==0);
            cntX1 += (s[i]=='X' && a[i]==1);
            cntX2 += (s[i]=='X' && a[i]==2);
        }

        for(int i=0; i<n; i++)
        {
            cntM0 += (s[i]=='M' && a[i]==0);
            cntM1 += (s[i]=='M' && a[i]==1);
            cntM2 += (s[i]=='M' && a[i]==2);
            cntX0 -= (s[i]=='X' && a[i]==0);
            cntX1 -= (s[i]=='X' && a[i]==1);
            cntX2 -= (s[i]=='X' && a[i]==2);

            if(s[i]=='E' && a[i]==0)
                ans += (cntM0*cntX2 + cntM2*cntX0 + cntM0*cntX0 + cntM2*cntX2);
            if(s[i]=='E' && a[i]==2)
                ans += (cntM0*cntX0 + cntM2*cntX0 + cntM0*cntX2);
        }
    }

    // mex = 2
    {
        ll int cntM0=0;
        ll int cntX0=0;
        ll int cntM1=0;
        ll int cntX1=0;

        for(int i=0; i<n; i++)
        {
            cntX0 += (s[i]=='X' && a[i]==0);
            cntX1 += (s[i]=='X' && a[i]==1);
        }

        for(int i=0; i<n; i++)
        {
            cntM0 += (s[i]=='M' && a[i]==0);
            cntM1 += (s[i]=='M' && a[i]==1);
            cntX0 -= (s[i]=='X' && a[i]==0);
            cntX1 -= (s[i]=='X' && a[i]==1);

            if(s[i]=='E' && a[i]==0)
                ans += 2ll*(cntM1*cntX1 + cntM0*cntX1 + cntM1*cntX0);
            if(s[i]=='E' && a[i]==1)
                ans += 2ll*(cntM0*cntX0 + cntM0*cntX1 + cntM1*cntX0);
        }
    }

    // mex = 3
    {
        ll int cntM0=0;
        ll int cntX0=0;
        ll int cntM1=0;
        ll int cntX1=0;
        ll int cntM2=0;
        ll int cntX2=0;

        for(int i=0; i<n; i++)
        {
            cntX0 += (s[i]=='X' && a[i]==0);
            cntX1 += (s[i]=='X' && a[i]==1);
            cntX2 += (s[i]=='X' && a[i]==2);
        }

        for(int i=0; i<n; i++)
        {
            cntM0 += (s[i]=='M' && a[i]==0);
            cntM1 += (s[i]=='M' && a[i]==1);
            cntM2 += (s[i]=='M' && a[i]==2);
            cntX0 -= (s[i]=='X' && a[i]==0);
            cntX1 -= (s[i]=='X' && a[i]==1);
            cntX2 -= (s[i]=='X' && a[i]==2);

            if(s[i]=='E' && a[i]==0)
                ans += 3ll*(cntM1*cntX2 + cntM2*cntX1);
            if(s[i]=='E' && a[i]==1)
                ans += 3ll*(cntM0*cntX2 + cntM2*cntX0);
            if(s[i]=='E' && a[i]==2)
                ans += 3ll*(cntM0*cntX1 + cntM1*cntX0);
        }
    }

    cout<<ans<<"\n";
}