//============================================================================
// Name        : HourRankA.cpp
// Author      : Luis Pujols
// Version     :
// Copyright   : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================

#include <iostream>
#include <set>
using namespace std;

int main() {
	int n;
	cin >> n;
	string s;
	cin >> s;
	set<char> special_characters = {'!','@','#','$','%','^','&','*','(',')','-','+'};
//	for(char v: special_characters){
//		cout << v << " ";
//	}
	int numbers = 0, low = 0, caps = 0, special = 0;
	for(int i = 0; i < s.length(); i++){
		if(s[i] >= '0' && s[i] <= '9') numbers++;
		else if(s[i] >= 'a' && s[i] <= 'z') low++;
		else if(s[i] >= 'A' && s[i] <= 'Z') caps++;
		else if(special_characters.count(s[i])) special++;
	}
//	cout << "numbs: " << numbers << " lows: " << low << endl;
//	cout << "caps: " << caps << " special: " << special << endl;
	int sol = 0;
	if(numbers < 1) sol++;
	if(low < 1) sol++;
	if(caps < 1) sol++;
	if(special < 1) sol++;

	if(sol + s.length() < 6){
		sol += 6 - (sol + s.length());
	}

	cout << sol << endl;

	return 0;
}