#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    bool lower=false, upper=false, digit=false, special=false;
    for(int i=0; i<n; i++){
        if(password[i]=='!'){
            special=true;
        }
        else if(password[i]=='@'){
            special=true;
        }
        else if(password[i]=='#'){
            special=true;
        }
        else if(password[i]=='$'){
            special=true;
        }
        else if(password[i]=='%'){
            special=true;
        }
        else if(password[i]=='^'){
            special=true;
        }
        else if(password[i]=='&'){
            special=true;
        }
        else if(password[i]=='*'){
            special=true;
        }
        else if(password[i]=='('){
            special=true;
        }
        else if(password[i]==')'){
            special=true;
        }
        else if(password[i]=='-'){
            special=true;
        }
        else if(password[i]=='+'){
            special=true;
        }
        else if(password[i]-'0'>=0 && password[i]-'0'<=9){
            digit=true;
        }
        else if(password[i]-'a'>=0 && password[i]-'a'<26){
            lower=true;
        }
        else if(password[i]-'A'>=0 && password[i]-'A'<26){
            upper=true;
        }
    }
    int ans=0;
    if(special==false){
        ans++;
    }
    if(digit==false){
        ans++;
    }
    if(lower==false){
        ans++;
    }
    if(upper==false){
        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;
}