#include <stdlib.h>  // NULL, EXIT_SUCCESS, malloc
#include <assert.h>  // assert (should normally only be used for testing)

typedef struct node_st {
  int element;
  struct node_st* next;
} Node;

Node* Push(Node* head, int e);

int main(int argc, char** argv) {
  Node* list = NULL;

  list = Push(list, 1);
  list = Push(list, 2);

  return EXIT_SUCCESS;
}

// add node with payload e to front of list head
// and return pointer to new node at front of list
Node* Push(Node* head, int e) {
  Node* n = (Node*) malloc(sizeof(Node));

  assert(n != NULL);  // crashes if false
  n->element = e;
  n->next = head;

  return n;
}