#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;


int main() {
    int n, left = 4;
    string str;
    
    cin >> n >> str;
    
    string numbers = "0123456789";
	string lower_case = "abcdefghijklmnopqrstuvwxyz";
	string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	string special_characters = "!@#$%^&*()-+";
	bool hasN = 0, hasL = 0, hasU = 0, hasS = 0;

	for (int i = 0; i < str.length() && !(hasN && hasL && hasU && hasS); ++i) {
		if (!hasN) hasN = numbers.find(str[i]) != string::npos;
		if (!hasL) hasL = lower_case.find(str[i]) != string::npos;
		if (!hasU) hasU = upper_case.find(str[i]) != string::npos;
		if (!hasS) hasS = special_characters.find(str[i]) != string::npos;
	}

	left = left - hasN - hasL - hasU - hasS;

	cout << max(6 - n, left);

	return 0;
}