#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    c=0
    #lower
    f=0
    for i in range(n):
        if('a'<=password[i]<='z'):
            f=1
    if(f!=1):
        c+=1
    
    #upper
    f=0
    for i in range(n):
        if('A'<=password[i]<='Z'):
            f=1
    if(f!=1):
        c+=1
        
    #digit
    f=0
    for i in range(n):
        if('0'<=password[i]<='9'):
            f=1
    if(f!=1):
        c+=1
        
    #char
    f=0
    for i in range(n):
        if(password[i] in list("!@#$%^&*()-+")):
            f=1
    if(f!=1):
        c+=1
    return(max(6-n,c))
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)