#!/bin/python

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
   
    num = lc = uc = sc = 1
    
    for ch in password:
        if ch in numbers:
            num = 0
        if ch in lower_case:
            lc = 0
        if ch in upper_case:
            uc = 0
        if ch in special_characters:
            sc = 0
    sum = num+lc+uc+sc 
    count = 0
    if(sum>0):
        count = sum
    
    if (len(password) + sum ) < 6:
        count += 6 - len(password) - sum 
        
    return count

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