Mobiles

input/code.cpp: In function 'int main()':
input/code.cpp:22:2: error: 'h' was not declared in this scope
  h(1, 1);
  ^
input/code.cpp: At global scope:
input/code.cpp:26:20: error: expected constructor, destructor, or type conversion at end of input
 __builtin_popcount()
                    ^

#include <iostream>
using namespace std;
int t[100001][2];
int k, l, n, e, y;
int g(int a){
	if (a==-1) return 1;
	int v=g(t[a][0]);
	int w=g(t[a][1]);
	if (__builtin_popcount(v)!=1 && __builtin_popcount(w)!=1) e=1;
	if (v<w) y++;
	if (v>2*w || w>2*v) e=1;
	return v+w;
}
int main(){
	cin >> n;
	for (int i=1; i<=n; ++i) {
		cin >> k >> l;
		t[i][0]=k;
		t[i][1]=l;
	}
	g(1);
	h(1, 1);
	if (e) cout << "-1\n";
	else cout << y << "\n";
}
__builtin_popcount()