Intersection Point in Y Shapped Linked Lists

/* Linked List Node
struct Node {
  int data;
  struct Node *next;
  Node(int x) {
    data = x;
    next = NULL;
  }
}; */

/* Should return data of intersection point of two linked
   lists head1 and head2.
   If there is no intersecting point, then return -1. */
int intersectPoint(Node* head1, Node* head2)
{
    Node *curr1=head1,*curr2=head2;
    while(curr1!=curr2){
        if(curr1==NULL)
            curr1=head2;
        else
            curr1=curr1->next;
        if(curr2==NULL)
            curr2=head1;
        else
            curr2=curr2->next;
    }
    return curr1->data;
}