#include<iostream>
using namespace std;
int main()
{
	for (int num = 1000; num <= 9999; num++) {
		int a = num/1000;
		int b = (num%100)/100;
		int c = (num%100)/10;
		int d = num%10;
		int tmp = d*1000 + c*100 + b*10 + a;
		if (num*9 == tmp)
			cout << num << endl;
	}
}