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