#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    int n2=0,l=0,u=0,s=0;
    for(int i=0;i<n;++i){
        if (!n2) for (auto &a:numbers){
            if(password[i]==a) n2=1;
        }
        
        if(!l) for(auto &a:lower_case) if(password[i]==a) l=1;
        if(!u) for(auto &a:upper_case) if(password[i]==a) u=1;
        if(!s) for(auto &a:special_characters) if(password[i]==a) s=1;
        
    }
    return max(6,n+4-n2-l-u-s)-n;
        
}

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