#include <cilk.h>
#include <cilk-lib.h>
#include <stdlib.h>
#include <stdio.h>

cilk int fib(int n)
{
     if (n < 2)
	  return (n);
     else {
	  int x, y;
	  x = spawn fib(n - 1);
	  y = spawn fib(n - 2);
	  sync;
	  return (x + y);
     }
}

cilk int main(int argc, char *argv[])
{
     int n, result;

     if (argc != 2) {
	  fprintf(stderr, "Usage: fib [<cilk options>] <n>\n");
	  Cilk_exit(1);
     }
     n = atoi(argv[1]);
     result = spawn fib(n);
     sync;

     printf("Result: %d\n", result);
     return 0;
}