#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* s) {
    int *count;
    char spe[]={'!','@','#','$','%','^','&','*','(',')','-','+'};
    count=calloc(4,sizeof(int));
    for(int j=0;s[j]!='\0';j++){
        if(count[0]==0){
            for(char i='a';i<='z';i++){
                if(s[j]==i){
                    count[0]++;
                    break;
                }
            }
        }
        if(count[1]==0){
            for(char i='A';i<='Z';i++){
                if(s[j]==i){
                    count[1]++;
                    break;
                }
            }
        }
        if(count[2]==0){
            for(char i='0';i<='9';i++){
                if(s[j]==i){
                    count[2]++;
                    break;
                }
            }
        }
        if(count[3]==0){
            for(int i=0;i<12;i++){
                if(s[j]==spe[i]){
                    count[3]++;
                    break;
                }
            }
        }
    }
        int len=strlen(s);
        int ans=0;
        if(count[0]==0) ans++;
        if(count[1]==0) ans++;
        if(count[2]==0) ans++;
        if(count[3]==0) ans++;
        if(len+ans<6){
            ans=(6-len-ans)+ans;
        }
        return ans;
}

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;
}