#include <math.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) {
    int i, c=0,flag[4],count=0,a=0,b=0;
    for(i = 0; i< 4; i++) {
       flag[i] = 0;
    }
    for(i = 0; i < n; i++) {
        if(password[i] >= 'A' && password[i] <= 'Z') {
            flag[0] = 1;
           
        }
        if(password[i] >= 'a' && password[i] <= 'z') {
            
            flag[1] = 1;
        }
        if(password[i] >= '0' && password[i] <= '9') {
            flag[2] = 1;
            
        }
        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] == '+')) {
                
            flag[3] = 1;
        }
    }
    for(i = 0; i< 4; i++) {
        if(flag[i] == 1) 
            count++;
    }
    
    b = (4 - count);
    c = n + b;
    
    if(c < 6) 
        a = 6-c;
    else 
        a = 0;
    
    c = b + a;
    return (c);
    
}

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