#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string passowrd) {
    int digit=0,special=0,lower=0,upper=0,ans=0;
    for(int i=0;i<n;i++) {
        if(passowrd[i] >=48 && passowrd[i] <= 57) {
            digit++;
        }
        else if(passowrd[i] >=97 && passowrd[i] <= 122) {
            lower++;
        }
        else if(passowrd[i] >=65 && passowrd[i] <= 90) {
            upper++;
        }
        else if(passowrd[i] == 33 || passowrd[i] == 64 || passowrd[i] == 94 || passowrd[i] == 35 || passowrd[i] == 36 || passowrd[i] == 37 || passowrd[i] == 38 || passowrd[i] == 42 || passowrd[i] == 40 || passowrd[i] == 41 || passowrd[i] == 43 || passowrd[i] == 45){
            special++;
        }
    }
    if(special == 0) {
        ans++;
    }
    if(lower == 0) {
        ans++;
    }
    if(upper == 0) {
        ans++;
    }
    if(digit == 0) {
        ans++;
    }
    if((n + ans) < 6) {
        ans += 6 - (n + ans);
    }
    return ans;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}