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