#include <iostream>
using namespace std;

int main(){
	int n, num = 0;
	cin >> n;
	for (int i = 10 ;i * i <= 999; i ++){
		int ans = i * i;
		int a = ans / 100;
		int b = ans / 10 % 10;
		int c = ans % 10;
		
		if (a == b || a == c|| b == c) {
			num++;
		}
		if (num == n){
			cout << ans;
			break;
		}
	}
	return 0;
}