Rectangle (AOJ 0345) by ynu_a
Contest: 3420    RunID: 2277069    Status: Accepted    Date: Sun Apr 23 15:42:13 JST 2017


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

int main() {
	
	int line[4] = {0};
	
	for(int i = 0; i < 4 ; i++){
		cin >> line[i];
	}
	sort(line,line + 4);
	
	if((line[0] == line[1]) && line[2] == line[3] ){
		cout << "yes" << endl;
	}else{
		cout << "no" << endl;
	}
		
	return 0;
}