#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    
    upp, low, spec, dig = 1, 1, 1, 1
    for i in password:
        if i in upper_case:
            upp = 0
        elif i in lower_case:
            low = 0
        elif i in numbers:
            dig = 0
        elif i in special_characters:
            spec = 0
        else:
            pass
    
    if len(password) >= 6:
        return upp + low + dig + spec
    else:
        return max(6 - len(password), (upp + low + dig + spec))

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