#!/bin/python

import sys

def minimumNumber(nn, a):
    # Return the minimum number of characters to make the password strong
    n = "0123456789"
    l = "abcdefghijklmnopqrstuvwxyz"
    u = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    s = "!@#$%^&*()-+"
    o1,o2,o3,o4 = 1,1,1,1
    for i in a:
        if i in n:
            o1 = 0
        if i in l:
            o2 = 0
        if i in u:
            o3 = 0
        if i in s:
            o4 = 0
    if nn + o1+o2+o3+o4 >= 6:
        return + o1+o2+o3+o4
    else:
        return 6-nn

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