#!/bin/python

import sys

def minimumNumber(n, password):
    count = 0
    numbers = "0123456789"
    upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    lower = "abcdefghijklmnopqrstuvwxyz"
    special = "!@#$%^&*()-+"

    if not any(x in numbers for x in password):
        count = count + 1
    if not any(x in upper for x in password):
        count = count + 1
    if not any(x in lower for x in password):
        count = count + 1
    if not any(x in special for x in password):
        count = count + 1

    if n+count < 6:
        count = count + (6-(n+count))

    return count

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