#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    bool dig=false,low=false,upp=false,spec=false;
    for (int i=0;i<password.length();i++){
        if (password[i]>='0'&&password[i]<='9'){
            dig=true;
        } else
        if (password[i]>='a'&&password[i]<='z'){
            low=true;
        } else
        if (password[i]>='A'&&password[i]<='Z'){
            upp=true;
        } else spec=true;
        
    }    
    int ans=4-upp-low-dig-spec;
    int lengt=password.length()+ans;
    if (lengt<6){
        return 6-password.length();
    }
    else return ans;
}
/*
Its length is at least .
It contains at least one digit.
It contains at least one lowercase English character.
It contains at least one uppercase English character.
It contains at least one special character. The special characters are: !@#$%^&*()-+
*/
int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    
    return 0;
}