#include <iostream>
using namespace std;
int main() {
	int a, b, c;
	cin >> a >> b >> c;
	if (a + c > b && a + c < b)
		cout << "Np" << "\n";
	else if (a + b > c && a + b < c)
		cout << "Np" << "\n";
	else if (b + c < a && b + c > a)
		cout << "Np" << "\n";
	else
		cout << "Yes << "\n";"
}