#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) {
    // Return the minimum number of characters to make the password strong
    int count=0;
    int flag1=0,flag2=0,flag3=0,flag4=0;
    for(int i=0;i<n;i++){
        if(password[i]>='0' &&password[i]<='9') flag1=1;
        if(password[i]>='a' &&password[i]<='z') flag2=1;
        if(password[i]>='A' &&password[i]<='Z') flag3=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]=='+') flag4=1;
    }
    if(!flag1) count++;
    if(!flag2) count++;
    if(!flag3) count++;
    if(!flag4) count++;
    
    if(n+count<6) return 6-n;
    else return count;
}

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;
}