#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    d, lc, uc, sp = False, False, False, False
    count = 0
    for x in password:
        if x.isupper():
            uc = True
        elif x.islower():
            lc = True
        elif x.isnumeric():
            d = True
        elif (x=='!') or (x=='@') or (x=='#') or (x=='$') or (x=='%') or (x=='&') or (x=='*') or (x=='(') or x==')' or (x=='-') or (x=='+'):
            sp = True
    if d is False:
        count+=1
    if lc is False:
        count+=1
    if uc is False:
        count+=1
    if sp is False:
        count+=1
    if n + count < 6:
        return 6-n
    return count

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