#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) 
{
    int d = 0, lc = 0, uc = 0, s = 0;
    int count = 0;
    for (int i = 0; i < n; i++)
    {
        if (password[i] >= 48 and password[i] <= 57) d++;
        else if (password[i] >= 65 and password[i] <= 90) uc++;
        else if (password[i] >= 97 and password[i] <= 122) lc++;
        else if (password[i] == 33 or password[i] == 64 or password[i] == '#' or password[i] == '$' or password[i] == '%' or password[i] == '^' or password[i] == '*' or password[i] == '(' or password[i] == ')' or password[i] == '-' or password[i] == '+')
        {
            s++;
        }
    }
    if (d < 1){
        count ++;
    }
    if (lc < 1){
        count ++;
    }
    if (uc < 1) {
        count ++;
    }
    if (s < 1) {
        count ++;
    }
    if (n < 6 and count < (6-n)) 
    {
        count += (6 - n - count);
    }
    
    return count;
}

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