#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,dc=0,uc=0,lc=0,sc=0,l=0,i,x=0;
    char s[200];
    scanf("%d", &n);
    scanf(" %s",s);
    for(i=0;i<n;i++)
    {
        if(s[i]>='a'&&s[i]<='z')
            lc++;
        else if(s[i]>='A'&&s[i]<='Z')
            uc++;
        else if(s[i]>='0'&&s[i]<='9')
            dc++;
        else if((s[i]>='!')||(s[i]>='@')||(s[i]>='#')||(s[i]>='$')||(s[i]>='%')||(s[i]>='^')||(s[i]>='&')||(s[i]>='*')||(s[i]>='(')||(s[i]>=')')||(s[i]>='-')||(s[i]>='+'))
            sc++;
    }
    if(n>6)
    {
        if(lc>=1&&uc>=1&&dc>=1&&sc>=1)
            printf("0");
        else
        {
            if(dc==0)
                x++;
            if(sc==0)
                x++;
            if(lc==0)
                x++;
            if(uc==0)
                x++;
            printf("%d",x);
        }
            
    }
    else
    {
        i=6-n;
        if(lc==0)
            x++;
        if(uc==0)
            x++;
        if(sc==0)
            x++;
        if(dc==0)
            x++;
        if(x+n>6)
            printf("%d",x);
        else
            printf("%d",x+(6-(x+n)));
    }
    return 0;
}