#!/bin/python3

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    hasNum = False
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    hasLower = False
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    hasUpper = False
    special_characters = "!@#$%^&*()-+"
    hasSpecial = False
    
    add = 0
    for char in password:
        if char in numbers and hasNum == False:
            hasNum = True
        if char in lower_case and hasLower == False:
            hasLower = True
        if char in upper_case and hasUpper == False:
            hasUpper = True
        if char in special_characters and hasSpecial == False:
            hasSpecial = True
    
    if hasNum == False:
        add += 1
    if hasLower == False:
        add += 1
    if hasUpper == False:
        add += 1
    if hasSpecial == False:
        add += 1
    
    if (add + n) < 6:
        add += 6 - (add + n)
    
    
    return add
    
    
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)