#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,lcase,ucase,scase,digit;
    if(n<6)
    {
        return 6-n;
    }
    else
    {
        for(i=0;i<n;i++)
        {
            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]=='+')
                scase++;
        
        if(password[i]>=65&&password[i]<=88)
            ucase++;
        if(password[i]>=97&&password[i]<=120)
            lcase++;
        if(password[i]>=48&&password[i]<=57)
            digit++;
        }
        if(digit==0)
            return 1;
        if(ucase==0)
            return 1;
        if(lcase==0)
            return 1;
        if(scase==0)
            return 1;
    }
}

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;
}