#!/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 = "!@#$%^&*()-+"
    
    changes = 0
    
    sc_ok = False
    for i in special_characters:
        if(i in password):
            sc_ok = True
            break
    if(not sc_ok):
        password += "!"
        changes += 1
        
    upp_ok = False
    for i in upper_case:
        if(i in password):
            upp_ok = True
            break
    if(not upp_ok):
        password += "A"
        changes += 1
    
    low_ok = False
    for i in lower_case:
        if(i in password):
            low_ok = True
            break
    if(not low_ok):
        password += "a"
        changes += 1
    
    dig_ok = False
    for i in numbers:
        if(i in password):
            dig_ok = True
            break
    if(not dig_ok):
        password += "0"
        changes += 1
    
    length = len(password)
    if(length < 6):
        changes += (6 - length)
    
    return changes
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)