#include <stdio.h>

struct st_pokemon //モンスターのステータス用構造体(体力・攻撃力)
{
	int hp;
	int attack;
};

int main(void)
{
	struct st_pokemon takahashi;
	struct st_pokemon aoki;
	int takahashi_judge	= 0;
	int aoki_judge 		= 0;

	scanf( "%d %d %d %d", &takahashi.hp , &takahashi.attack , &aoki.hp , &aoki.attack );
	
	takahashi_judge = takahashi.hp - aoki.attack;
  	aoki_judge		= aoki.hp - takahashi.attack;

	if( takahashi_judge >= aoki_judge )
	{
		printf("Yes");
	}
	else
	{
		printf("No");
	}
 
 	return;
}