#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    bool cap = 0 , small = 0 , sp = 0 , di = 0 ;
    
    
    for(int i = 0 ; i < n ; i++){
        if( password[i] <= 57 && password[i] >= 48 ) di = 1;
        
        if( password[i] <= 90  && password[i] >= 65 ) cap = 1;
        if( password[i] <= 122  && password[i] >= 97 ) small = 1;
        if( password[i] == 33 ||  password[i] == 35 || password[i] == 37 ||( password[i] <= 45  && password[i] >= 40 ) || password[i] == 64) sp = 1;
    }
    
   
    
    int sum = 4 -(di + small + cap + sp);
    
    
    if( 6-n <= 0) return sum;
    else if (6 <= sum + n) return sum;
    else  return 6-n;
}    
    

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