if (x1 == x2) {

return "YES";

} else if ((x1 < x2 && v1 > v2) || (x1 > x2 && v1 < v2)) {

float t;

t = (float) (x2 - x1) / (float) (v1 - v2);

if (floor(t) == t) {

return "YES";

}

}

return "NO";

int x1;

int v1;

int x2;

int v2;

cin >> x1 >> v1 >> x2 >> v2;

string result = kangaroo(x1, v1, x2, v2);

cout << result << endl;

return 0;