#include <iostream>

int main(){
	double x, y, r;
	std::cout << "x = ";
	std::cin >> x;
	std::cout << "y = ";
	std::cin >> y;
	std::cout << "r = ";
	std::cin >> r;
	
	if (x >= 0.0 && y <= 0.0 && x <= r / 2.0 && y >= -r){
		std::cout << "Belongs" << std::endl;
	} else if (x < 0.0 && y < 0.0 && x * x + y * y <= (r / 2.0) * (r / 2.0)) {
		std::cout << "Belongs" << std::endl;
	} else if (x <= 0.0 && y >= 0.0 && ((x + r) * (r / 2.0) - y * r) >= 0.0) {
		std::cout << "Belongs" << std::endl;
	} else {
		std::cout << "Not Belongs" << std::endl;
	}
}