#include <iostream>

using namespace std;

int main() {
    int n;
    string s;

    cin >> n >> s;
    bool lower = false, upper = false, special = false, digit = false;

    for (int i = 0; i < n; i++)
        if (s[i] >= 'a' && s[i] <= 'z')
            lower = true;
        else if (s[i] >= 'A' && s[i] <= 'Z')
            upper = true;
        else if (s[i] >= '0' && s[i] <= '9')
            digit = true;
        else if (string("!@#$%^&*()-+").find(s[i]) != string::npos)
            special = true;

    int ans = int(!lower) + int(!upper) + int(!special) + int(!digit);
    while (ans + n < 6)
        ans++;

    cout << ans << endl;    
}