#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 num=0,sc=0,lc=0,uc=0;
    for(int i=0;i<n;i++)
    {
        if(password[i]<='9'&&password[i]>='0')
            num++;
        if(password[i]<='z'&&password[i]>='a')
            lc++;
        if(password[i]<='Z'&&password[i]>='A')
            uc++;                     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]=='+')
            sc++;
    }
    int count=0;
    if(num==0)
        count++;
    if(lc==0)
        count++;
    if(uc==0)
        count++;
    if(sc==0)
        count++;
    if(n>=6)
        return count;
    else 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;
}