#include <vector>
#include <iostream>

using namespace std;

struct node {
	node *l, *r;
	int x;
};

void dfs(int v) {
	printf("dfs(v=%d)\n", v);
	dfs(v);
}

void out(node *v, int dep = 0) {
	if (!v)
		return;
	out(v->l, dep + 1);
	printf("%*sx=%d\n", 2 * dep, "", v->x);
	out(v->r, dep + 1);
}

int main() {

}