program answer
  implicit none

  integer :: A, V, B, W, T

  read(*,*) A, V
  read(*,*) B, W
  read(*,*) T

  if(B+W*T<=A+V*T) then
     write(*,*) 'YES'
  else
     write(*,*) 'NO'
  end if

  stop
 end program answer