function kangaroo(x1, v1, x2, v2) {
    for(let i=0;i<=10000;i++){
        if(x1 === x2){
            return 'YES'
        }
        x1+=v1
        x2+=v2
    }
    return 'NO'
}

function kangaroo($x1, $v1, $x2, $v2) {
    // Write your code here
$pk1 = $x1; //position kangaroo No1
$pk2 = $x2; //position kangaroo No2
    if ($x1 == $x2 && $v1 != $v2 or
        $x1 != $x2 && $v1 == $v2 or
        $x1 > $x2 && $v1 > $v2 or
        $x1 < $x2 && $v1 < $v2) {
        return "NO";
    }else if ($x1 < $x2) {
        for ($t=1; $pk1<=$pk2; $t++) {
            if (($pk1 +($v1*$t)) == ($pk2 + ($v2*$t))) {
            return "YES";
            } else if (($pk1 +($v1*$t)) > ($pk2 + ($v2*$t))) {
            return "NO";
            }
        }
    }else if ($x2 < $x1) {
        for ($t=1; $pk2<=$pk1; $t++) {
            if (($pk1 +($v1*$t)) == ($pk2 + ($v2*$t))) {
            return "YES";
            } else if (($pk1 +($v1*$t)) < ($pk2 + ($v2*$t))) {
            return "NO";
            }
        }
    } else return "NO";
}

def kangaroo(x1, v1, x2, v2):
    if ((x1 > x2 and v1 >= v2) or (x2 > x1 and v2 >= v1)) or ((x1 - x2) %  (v2-v1) != 0) :
        return 'NO'
    return 'YES'

def kangaroo(x1, v1, x2, v2):
    
    # Image the time in an x axis 
    # and position in a y axis
    # kangaroo movements can be represented by two straight lines
    
    if v1 == v2:
        if x1 == x2:
            # They are always moving 
            # in the same locations
            # at the same time
            return "YES"
        else:
            # Same velocity but different initial positions
            return "NO"
    
    num = x2 - x1
    den = v1 - v2
    
    if num / den < 0:
        # Intersection of the two lines happens before x=0 (initial time)
        return "NO"

    if num % den == 0:
        # Intersection happens in a specific location
        return "YES"
    
    # Intersection happens, but not in a quantized world made by jumps
    return "NO"