def kangaroo(x1, v1, x2, v2):
    return 'YES' if v1 > v2 and (x2-x1) % (v1-v2) == 0 else 'NO'
    
    #general case (no constain x1 < x2)
    # if v1 == v2:
    #     return 'YES' if x1 == x2 else 'NO'
    # return 'YES' if (x2-x1) / (v1-v2) >= 0 and (x2-x1) % (v1-v2) == 0 else 'NO'