#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <ctype.h>

int minimumNumber(int n, char* password) {
    // Return the minimum number of characters to make the password strong
    // Special_characters = "!@#$%^&*()-+"
    int digit = false, upper = false, lower = false, special = false;
    
    for (int a = 0; a < n; a++) {
        if (isupper(password[a])) upper = true;
        else if (islower(password[a])) lower = true;
        else if (isdigit(password[a])) digit = true;
        else {
            switch (password[a]) {
                case '!': case '@': case '#': case '$':
                case '%': case '^': case '&': case '*':
                case '(': case ')': case '-': case '+':
                    special = true;
            }
        }
    }
    
    int add = 4 - (digit + upper + lower + special);
    
    if ((n+add) >= 6) return add;
    else return 6-n;
}

int main() {
    int n; 
    scanf("%i", &n);
    char* password = (char *)malloc(512000 * sizeof(char));
    scanf("%s", password);
    int answer = minimumNumber(n, password);
    printf("%d\n", answer);
    return 0;
}