#include <bits/stdc++.h>

using namespace std;

string str;

int main() {
    int n, aux, i;
    cin >> n;
    aux = n;
    cin >> str;
    int cnt1 = 0, cnt2 = 0, cnt3 = 0, cnt0 = 0;
    str = " " + str;
    for(i = 1; i <= n; i++) {
        if(str[i] >= '0' && str[i] <= '9')
            cnt0 = 1;
        if(str[i] >= 'a' && str[i] <= 'z')
            cnt1 = 1;
        if(str[i] >= 'A' && str[i] <= 'Z')
            cnt2 = 1;
        if(str[i] == '!' || str[i] == '@' || str[i] == '#' || str[i] == '$' || str[i] == '%' || str[i] == '^' || str[i] == '&' || str[i] == '*' || str[i] == '(' || str[i] == ')' || str[i] == '-' || str[i] =='+')
            cnt3 = 1;
    }
    n += 4 - cnt1 - cnt2 - cnt3 - cnt0;
    if(n < 6)
        n = 6;
    cout << n - aux;
    return 0;
}