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


#!/bin/python3

import sys
store = {
    'numbers' : 1,
    'lower_case' : 1,
    'upper_case' : 1,
    'special_characters' : 1
}
def minimumNumber(n, password):
    for character in list(password):
        if character in numbers:
            store['numbers'] = 0
        if character in upper_case:
            store['upper_case'] = 0
        if character in lower_case:
            store['lower_case'] = 0
        if character in special_characters:
            store['special_characters'] = 0
    required_sum = sum(x for x in store.values())
    if len(password) > 5:
        return required_sum
    else:
        return max((6 - n), required_sum)

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