#include <iostream>
#include <string>
using namespace std;

int cw(char t[], int s){
    int count = 0;
    for (int i = 0; i < s; i++){
        if (t[i] == '_'){
            count++;
        }
    }
    return count;
}

int n;
int main(){
    cin >> n;
    char N[n];
    int value = 1;
    const int c = cw(N, n);
    for (int i = 0; i < n; i++){
        cin >> N[i];
    }
    value = 26 - (n-c);
    for (int i = c; i > 1; i--){
        value *= 26-i;
    }
    cout << value;
    return 0;
}