#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
	numbers = "0123456789";
	lower_case = "abcdefghijklmnopqrstuvwxyz";
	upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	special_characters = "!@#$%^&*()-+";
	
	passDict = dict();
	
	for a in range(len(numbers)):
		passDict[numbers[a]] = 'NB';
	
	for b in range(len(lower_case)):
		passDict[lower_case[b]] = 'LC';
	
	for c in range(len(upper_case)):
		passDict[upper_case[c]] = 'UC';
		
	for c in range(len(special_characters)):
		passDict[special_characters[c]] = 'SC';
	
	isNB=1;
	isLC=1; 
	isUC=1; 
	isSC=1;
	
	for i in range(n):
		charType = passDict[password[i]];
		
		if charType == 'NB':
			isNB = 0;
		elif charType == 'LC':
			isLC = 0;
		elif charType == 'UC':
			isUC = 0;
		elif charType == 'SC':
			isSC = 0;
			
	rqdLen = max((6 - n),0);
	rqdChar = isNB + isLC + isUC + isSC;
	
	return max(rqdChar, rqdLen);
	

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