#!/bin/python3

import sys
s=list('!@#$%^&*()-+')
def minimumNumber(n, password):
    num =len(password)
    count=0
    x1=[1 for i in password if(i.islower())]
    x2=[1 for i in password if(i.isupper())]
    x3=[1 for i in password if(i.isdigit())]
    x4=[1 for i in password if(i in s)]
    if x1==[]:
        count+=1
    if x2==[]:
        count+=1
    if x3==[]:
        count+=1
    if x4==[]:
        count+=1
    if num+count>=6:
        return(count)
    if num+count<6:
        return(6-num)
    # Return the minimum number of characters to make the password strong

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