#!/bin/python

import sys

def minimumNumber(n, password):
    num = 1;
    cap = 1;
    small = 1;
    sp = 1;
    for i in password:
        if ord('0') <=ord(i) <= ord('9'):
            num = 0;
        if ord('a') <= ord(i) <= ord('z'):
            small = 0;
        if ord('A') <= ord(i) <= ord('Z'):
            cap = 0;
        if i in "!@#$%^&*()-+":
            sp = 0;
    return max(num+cap+small+sp,6-n);

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