#!/bin/python3

import sys

def minimumNumber(n, password):
    cond= [1,1,1,1]
    numbers = list("0123456789")
    lower_case = list("abcdefghijklmnopqrstuvwxyz")
    upper_case = list("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
    special_characters = list("!@#$%^&*()-+")
    p = list(password)
    for i in p:
        if i in numbers:
            cond[0] = 0
        if i in lower_case:
            cond[1] = 0
        if i in upper_case:
            cond[2] = 0
        if i in special_characters:
            cond[3] = 0
    s = sum(cond)
    if n >= 6:
        return s
    elif n + s < 6:
        return 6 - n
    else:
        return s
    

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