#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int n, ans=0, i, num=0, lo=0, up=0, sp=0, j;
    
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    string s;
    
    cin >> n;
    cin >> s;
    
    for(i=0; i<n; i++){
        if(s[i] >= '0' && s[i] <= '9'){
            num++;
        }
        else if(s[i] >= 'a' && s[i] <= 'z'){
            lo++;
        }
        else if(s[i] >= 'A' && s[i] <= 'Z'){
            up++;
        }
        else{
            sp++;
        }
    }
    
    /*for(i=0; i<n; i++){
        for(j=0; i<numbers.size(); j++){
            if(s[i] == numbers[i]){
                num++;
            }
            else{
                for(j=0; i<lower_case.size(); j++){
                    if(s[i] == lower_case[i]){
                        lo++;
                    }
                    else{
                        for(j=0; i<upper_case.size(); j++){
                            if(s[i] == upper_case[i]){
                                up++;
                            }
                            else{
                                for(j=0; i<special_characters.size(); j++){
                                    if(s[i] == special_characters[i]){
                                        sp++;
                                    }
                                    else{
                                        for(j=0; i<upper_case.size(); j++){
                                            if(s[i] == upper_case[i]){
                                                up++;
                                            }
                                        }
                                    }                      
                                }
                            }
                        }
                    }
                }
           }
        }
    }*/   
    if(num == 0){
        ans++;
    }
    if(lo == 0){
        ans++;
    }
    if(up == 0){
        ans++;
    }
    if(sp == 0){
        ans++;
    }
    if(n+ans < 6){
        ans += 6-n-ans;
    }
    cout << ans << endl;
    
    
    return 0;
}