#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    set<char> special = {'!','@','#','$','%','^','&','*','(',')','-','+'};
    vector<int> cond(4,0);
    for(int i=0;i<password.length();i++){
        if(password[i]>='0' && password[i]<='9') cond[0]++;
        else if(password[i]>='a' && password[i]<='z') cond[1]++;
        else if(password[i]>='A' && password[i]<='Z') cond[2]++;
        else if(special.find(password[i]) != special.end()) cond[3]++;
    }
    int count = 0;
    for(int i=0;i<4;i++){
        if(cond[i] == 0) count++;
    }
    if(password.length()+count < 6) return 6-password.length();
    else return count;
}

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