#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 size;
    cin >> size;
    string password;
    cin >> password;
    int chars_to_add = 0;
    bool has_digit = false;
    bool has_lower = false;
    bool has_upper = false;
    bool has_special = false;
    for (int i =0 ; i < size; i++) {
        if ((password[i] >= 'a') && password[i] <= 'z') {
            has_lower = true;
            //cerr << "Has lower case" <<endl;
        } else if ((password[i] >= 'A') && password[i] <= 'Z') {
            has_upper = true;
            //cerr << "Has upper case" <<endl;
        } else if ((password[i] >= '0') && password[i] <= '9') {
            has_digit = true;
            //cerr << "Has digit case" <<endl;
        } else if ((password[i] == '!') || (password[i] == '@')  || (password[i] == '#')
                   || (password[i] == '$')|| (password[i] == '%')|| (password[i] == '^')
                   || (password[i] == '&')|| (password[i] == '*')|| (password[i] == '(')
                   || (password[i] == ')')|| (password[i] == '-')|| (password[i] == '+')) {
            //!@#$%^&*()-+
            has_special = true;
            //cerr << "Has digit case" <<endl;
        }

    }
    if (!has_digit) chars_to_add++;
    if (!has_lower) chars_to_add++;
    if (!has_upper) chars_to_add++;
    if (!has_special) chars_to_add++;
    if (size < 6)
        chars_to_add = max (chars_to_add, (6 - size));
    
    cout << chars_to_add<< endl;
    return 0;
}