text: #!/bin/python3
  
  import sys
  
  x1, v1, x2, v2 = map(int, input().strip().split(' '))
  
  willLand = (
      v1 != v2
      and (x1 - x2) %  (v2 - v1) == 0 
      and (x1 - x2) // (v2 - v1) >= 0)
  
  print(('NO', 'YES')[willLand])
  