#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    ans = 0
    t = {}
    
    d = 0 
    lc = 0
    uc = 0 
    sc = 0
    
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    
    for e in password :
        if e in numbers :
            d = d +1
        if e in lower_case :
            lc += 1
        if e in upper_case :
            uc = uc +1
            
        if e in special_characters :
            sc += 1    
        
    
    if d == 0:
        ans += 1
        n +=1
    if uc == 0:
        ans += 1
        n +=1
    if lc == 0:
        ans += 1
        n +=1
    if sc == 0:
        ans += 1
        n +=1
    if n <6 :
        return (6 - n + ans)
    else :
        return ans
    
    
    
    
    

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