#!/bin/python

import sys,re

def minimumNumber(n, password):
    if n!=0:
        sp=0
        lc=0
        up=0
        d=0
        for i in range(n):
            if password[i].isdigit():
                d=1
            elif password[i].isupper():
                up=1
            elif password[i].islower():
                lc=1
            else:
                sp=1
        count=0
        if sp==0:
            count+=1
        if lc==0:
            count+=1
        if up==0:
            count+=1
        if d==0:
            count+=1
        if n+count<6:
            count+=(6-n-count)
        return count

if __name__ == "__main__":
    n = int(raw_input().strip())
    password = raw_input().strip()
    answer = minimumNumber(n, password)
    print answer