#include <iostream>
using namespace std;
int main()
{
	int counter = 1;
	int left, right;
	cout << "Enter Two Numbers" << endl;
	cin >> right >> left;
while (left<0 || right<0 || left>right)
{
	if (counter == 3)
	{
		cout << "Three mistakes" << endl;
		break;
	}
	cout<< "Invalid Input" << endl;
	cout<< "Enter Two Numbers" << endl;
	cin >> right >> left;
	counter++;
}
	return 0;
}