#include <iostream>
#include <string>
using namespace std;

int main()
{
	string str1, str2, str3, str4;
	while (cin >> str1 >> str2 >> str3 >> str4)
	{
		if (str3[0] >= str1[0] && str3[0] <= str2[0] || str4[0] >= str1[0] && str4[0] <= str2[0])
			cout << "Overlap IP" << endl;
		else
			cout << "No Overlap IP" << endl;
	}
	return 0;
}