#!/bin/python3

import sys

numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    errorcnt = 0
    for num in numbers:
        if num in password:
            break
    else:
        errorcnt += 1
    
    for l in lower_case:
        if l in password:
            break
    else:
        errorcnt += 1
        
    for u in upper_case:
        if u in password:
            break
    else:
        errorcnt += 1
        
    for s in special_characters:
        if s in password:
            break
    else:
        errorcnt += 1
        
        
    if n + errorcnt >= 6:
        return errorcnt
    else:
        return 6 - n

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