#include <bits/stdc++.h>

using namespace std;

vector<bool> allCase(4,false);

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    
    int i = 0;
    string sc = "!@#$%^&*()-+";
    
    while(password[i]){
        if(password[i]>='a' && password[i]<='z')    allCase[0] = true;
        if(password[i]>='A' && password[i]<='Z') allCase[1] = true;
        if(password[i]>='0' && password[i]<='9') allCase[2] = true;
        for(int j=0; j<sc.length(); ++j){
            if(password[i]==sc[j]) { allCase[3] = true; break;}
        }
        ++i;
    }
    
    int cnt = 4;
    
    for(i=0; i<4; ++i){
        if(allCase[i]) --cnt;
    }
    
    if((n+cnt)<6)
        cnt = 6 - n;
    
    return cnt;
    
}

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