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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n ;
    string str;
    cin >> n;
    cin >> str;
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    char n_flag = 'n';
    char l_flag = 'n';
    char u_flag = 'n';
    char s_flag = 'n';
    char ch;
    for(int i = 0 ; i < n ; i++){
        ch = str.at(i);
        if(n_flag == 'n'){
            for(int j = 0 ; j < numbers.length() ; j++)
                if(ch == numbers.at(j)){
                    n_flag = 'y';
                    break;
                }
        }
        if(l_flag == 'n'){
            for(int j = 0 ; j < lower_case.length() ; j++)
                if(ch == lower_case.at(j)){
                    l_flag = 'y';
                    break;
                }
        }
        if(u_flag == 'n'){
            for(int j = 0 ; j < upper_case.length() ; j++)
                if(ch == upper_case.at(j)){
                    u_flag = 'y';
                    break;
                }
        }
        if(s_flag == 'n'){
            for(int j = 0 ; j < special_characters.length() ; j++)
                if(ch == special_characters.at(j)){
                    s_flag = 'y';
                    break;
                }
        }
    }
    int k = 0;
    if(n_flag == 'n')
        k++;
    if(l_flag == 'n')
        k++;
    if(u_flag == 'n')
        k++;
    if(s_flag == 'n')
        k++;
    int res = 0;
    if(n < 6){
    
        if((k - (6-n)) > 0)
            res = (6-n) + (k-(6-n));
        else
            res = (6-n);
    }    
    else
        res = k;
    cout << res;
    return 0;
}