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

int minimumNumber(int n, char* password) {
    // Return the minimum number of characters to make the password strong
    int i, d = 0, l = 0, u = 0, s = 0, c = 0;
    for(i = 0; i < n; i++)
    {
        if(isdigit(password[i]))
            d++;
        else if(islower(password[i]))
            l++;
        else if(isupper(password[i]))
            u++;
        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] == '+')
            s++;
    }
    if(d == 0)
         c++;
    if(l == 0)
         c++;
    if(u == 0)
         c++;
    if(s == 0)
         c++;
    if(n + c < 6)
        c = 6 - n;
    return c;
}

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