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



int main() {
    int n; 
    scanf("%i", &n);
    char* pass = (char *)malloc(n * sizeof(char));
    scanf("%s", pass);
    
    int i;
    
        int c=0;
    for(i=0;i<n;i++){
        if(pass[i]>=97 && pass[i]<=122){
            c++;
            break;
        }
        
    }
    for(i=0;i<n;i++){
        if(pass[i]>=65 && pass[i]<=90){
            c++;
            break;
        }
    }
    for(i=0;i<n;i++){
        if(pass[i]>=48 && pass[i]<=57){
            c++;
            break;
        }
    }
    for(i=0;i<n;i++){
        if(pass[i]==33 || pass[i]==64 || pass[i]==35 || pass[i]==36 || pass[i]==37 || pass[i]==94 || pass[i]==38 || pass[i]==42 || pass[i]==40 || pass[i]==41 || pass[i]==43 || pass[i]==45){
            c++;
            break;
        }
    }
    if(strlen(pass)>=6)
    printf("%d\n",4-c);
    else{
        if(6-n>4-c)
        printf("%d\n",6-n);
        else printf("%d\n",4-c);
        
    }
    
    return 0;
}