#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    no, lo, up, sp = True, True, True, True
    count = 4
    sp_char = "!@#$%^&*()-+"
    
    for l in password:
        c = ord(l)
        
        if no and 47 < c < 58:
            no = False
            count -= 1
        elif lo and 96 < c < 123:
            lo = False 
            count -= 1
        elif up and 64 < c < 91:
            up = False 
            count -= 1
        elif sp and l in sp_char:
            sp = False 
            count -= 1
        if count == 0:
            break

    return max(6-n,count)  
    

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