#!/bin/python3

import sys

def minimumNumber(n, password):
    nums = list("0123456789")
    lower = list("abcdefghijklmnopqrstuvwxyz")
    upper = list("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
    special = list("!@#$%^&*()-+")
    u = False
    l = False
    s = False
    n = False
    for i in password:
        if i in upper: u = True
        elif i in lower: l = True
        elif i in special: s = True
        elif i in nums: n = True
    ls = len(password)
    count = 0
    if not u: count += 1
    if not l: count += 1
    if not s: count += 1
    if not n: count += 1
    diff = 0
    if count + ls < 6: diff = 6-count-ls
    return count+diff
        
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)