#!/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
    noNum = 1
    noLower = 1
    noUpper = 1
    noSpec = 1
    for i in range(n):
        if password[i] in numbers:
            #print('a')
            noNum = 0
        if password[i] in lower_case:
            #print('b')
            noLower = 0
        if password[i] in upper_case:
            #print('c')
            noUpper = 0
        if password[i] in special_characters:
            #print('d')
            noSpec = 0
        
    charshort = max([0,6-n])
    #print(noNum ,noLower , noUpper , noSpec)
    #print(charshort)
    specs = noNum + noLower + noUpper + noSpec
    return max([charshort,specs])
        
    

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