/in/foo.c:6:5: error: unknown type name 'Node'
     Node* next;
     ^~~~
/in/foo.c:9:18: error: unknown type name 'Node'
 int FindAscCount(Node* head)
                  ^~~~
/in/foo.c:37:1: error: unknown type name 'Node'
 Node* InsertNode(Node* head, int data)
 ^~~~
/in/foo.c:37:1: note: use 'struct' keyword to refer to the type
/in/foo.c:37:18: error: unknown type name 'Node'
 Node* InsertNode(Node* head, int data)
                  ^~~~
/in/foo.c: In function 'main':
/in/foo.c:61:5: error: unknown type name 'Node'
     Node* head1 = NULL;
     ^~~~
/in/foo.c:61:5: note: use 'struct' keyword to refer to the type
/in/foo.c:62:5: error: unknown type name 'Node'
     Node* head2 = NULL;
     ^~~~
/in/foo.c:62:5: note: use 'struct' keyword to refer to the type
/in/foo.c:69:15: warning: implicit declaration of function 'InsertNode' [-Wimplicit-function-declaration]
         head1=InsertNode(head1, num);
               ^~~~~~~~~~
/in/foo.c:69:14: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
         head1=InsertNode(head1, num);
              ^
/in/foo.c:75:14: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
         head2=InsertNode(head2, num);
              ^
/in/foo.c:77:21: warning: implicit declaration of function 'FindAscCount' [-Wimplicit-function-declaration]
     int ascCount1 = FindAscCount(head1);
                     ^~~~~~~~~~~~