#include<stdio.h>
int main(void){
  	int a,b,c,d;
  	int t = 1;
  int g;
  scanf("%d%d%d%d\n",&a,&b,&c,&d);
  	while(&t != 0){
      	t = c - b;
      	g = a - d;
    }
  if(t <= 0){
	printf("No");
  }else{
    printf("Yes");
  }
  return 0;
}