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