#!/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 = "!@#$%^&*()-+"
    nos=list(numbers)
    lc=list(lower_case)
    uc=list(upper_case)
    sc=list(special_characters)
    vnos=1
    vlc=1
    vuc=1
    vsc=1
    p=list(password)
    for i in p:
        if i in nos:
            vnos=0
        elif i in uc:
            vuc=0
        elif i in lc:
            vlc=0
        elif i in sc:
            vsc=0
    if(len(p)+vnos+vuc+vlc+vsc)<6:
        return 6-len(p)
    return vnos+vuc+vlc+vsc
    
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)