#!/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 = "!@#$%^&*()-+"
    passw = password.replace(' ',"")

    lp = len(passw)
    if lp<=0:
        return 6
    
    
    isD = False
    isU = False
    isL = False
    isS = False
    for i in range(len(passw)):
        if passw[i] in numbers:
            isD = True
        if passw[i] in upper_case:
            isU = True
        if passw[i] in lower_case:
            isL = True
        if passw[i] in special_characters:
            isS = True
        if (not isD) and (not isU) and (not isL) and (not isS):
            lp = lp - 1
            
        
    ans = 0
    if not isD:
        ans += 1
    if not isU:
        ans += 1
    if not isL:
        ans += 1
    if not isS:
        ans += 1

    res = max(ans, 6-lp)
    return res

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