import sys


def kangaroo(x1, v1, x2, v2):
    if v2>=v1:
        return "NO"
    else:
        if (x2-x1)%(v1-v2)==0:
            return "YES"
        else:
            return "NO"

if __name__ == '__main__':
  x1,v1,x2,v2 = list(map(int,input().strip().split(' ')))
  result = kangaroo(x1, v1, x2, v2)
  print(result)