// External Function (prototype)
printf(fmt, args);
scanf(fmt, args);

// Tower of Hanoi
hanoi(n, x, y, z) {
  if (n == 0) return;
  hanoi(n-1, x, z, y);
  printf("Move %d from %s to %s\n", n, x, y);
  hanoi(n-1, z, y, x);
}

// Main routine
main() {
  var n[1];
  printf("N? "); scanf("%d", n);
  hanoi(n[0] , "A", "C", "B");
}