#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int check1(char c){
	if ('0' <= c && c <= '9') return 1;
	else return 0;
}
int check2(char c) {
	if ('a' <= c && c <= 'z') return 1;
	else return 0;
}
int check3(char c) {
	if ('A' <= c && c <= 'Z') return 1;
	else return 0;
}
int check4(char c) {
	char c1 = '!'; char c2 = '@'; char c3 = '#'; 
	char c4 = '$'; char c5 = '%'; char c6 = '^'; 
	char c7 = '&'; char c8 = '*'; char c9 = '('; 
	char c10 = ')'; char c11 = '-'; char c12 = '+';
	if (c == c1 || c == c2 || c == c3 || c == c4 || c == c5 || c == c6 || c == c7 || c == c8 || c == c9 || c == c10 || c == c11 || c == c12) return 1;
	else return 0;
}

int minimumNumber(int n, string password) {
	// Return the minimum number of characters to make the password strong
	bool ch1 = true, ch2 = true, ch3 = true, ch4 = true;
	int ret = 0;
	if (n == 0)
		return 6;
	else if (n == 1) 
		return 5;
	else if (n == 2) 
		return 4;
	else if (n == 3) 
		return 3;
	else {
		for (int i = 0; i < n; i++) {
			if (ch1 && check1(password[i])) {
				ch1 = false;
				ret = ret + 1;
			}
			else if(ch2 && check2(password[i])) {
				ch2 = false;
				ret = ret + 1;
			}
			else if(ch3 && check3(password[i])) {
				ch3 = false;
				ret = ret + 1;
			}
			else if(ch4 && check4(password[i])) {
				ch4 = false;
				ret = ret + 1;
			}
		}
		return max(6-n, 4 - ret);
	}
}

int main() {
	int n;
	cin >> n;
	string password;
	cin >> password;
	int answer = minimumNumber(n, password);
	cout << answer << endl;
	return 0;
}