/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function FindFirstCommonNode(pHead1, pHead2)
{
    // write code here
    var p1 = pHead1,
        p2 = pHead2;
    while(p1 != p2) {
        p1 = p1 == null ? pHead2 : p1.next;
        p2 = p2 == null ? pHead1 : p2.next;
    }
    return p1;
}