global path1 = int[]{0, 0, 1};
global path2 = int[]{1, 1, 0};

struct Node {
  int val;
  Node left;
  Node right;
  (int, int) -> int fun
}

int sum_plus_one(int x, int y) {
  return x+y+1;
}

int two_x_plus_y(int x, int y) {
  return 2*x+y;
}

void make_children(Node root, int depth) {
  if (depth != 0) {
    var left_node = new Node{val=root.fun(root.val, 0); left=Node null; right=Node null; fun=root.fun};
    make_children(left_node, depth-1);
    var right_node = new Node{val=root.fun(root.val, 1); left=Node null; right=Node null; fun=root.fun};
    make_children(right_node, depth-1);
    root.left = left_node;
    root.right = right_node;
  }
  return;
}

int retrieve(Node root, int depth, int[] path) {
  var next = root.right;
  if (path[depth] == 0) {
    next = root.left;
  }
  if (depth == 0) {
    return next.val;
  } else {
    return retrieve(next, depth-1, path);
  }
}

int program(int argc, string[] argv) {
  var root1 = new Node{val=1; left=Node null; right=Node null; fun=sum_plus_one};
  var root2 = new Node{val=2; left=Node null; right=Node null; fun=two_x_plus_y};
  make_children(root1, 3);
  make_children(root2, 3);
  if (retrieve(root1, 2, path1) == 5 & retrieve(root2, 2, path2) == 19) {
    return 1;
  } else {
    return 0;
  }
}