program b1

 implicit none

 integer :: a,b,c,d,i,x,y

 read*,a,b,c,d

 do i=1,1000 
   x=c-b
   if(x<=0) print*,"Yes"
   if(x<=0) exit
   y=a-d 
   if(y<=0) print*,"No"
   if(y<=0) exit
   c=x
   a=y
 end do
 

end program b1