/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) {
        if(pHead1 == null || pHead2 == null){
            return null;
        }
        ListNode point1 = pHead1;

        while(point1 != null){
            ListNode point2 = pHead2;
            while(point2 != null){
                if(point1 == point2){
                    return point1;
                }
                point2 = point2.next;
            }
            point1 = point1.next;
        }
        return null;
    }
}