rt，这题不会真的退役吧

#include <bits/stdc++.h>

using namespace std;

int t;
int n, p;

void dfs(int x, int k) {
	if (x / 2 < k) {
		cout << "-1" << endl;
		return ;
	}
	if (k == 0) {
		for (int i = 1; i <= x; i++) {
			cout << "0" ;
		}
		cout << endl;
		return ;
	}
	for (int i = 1; i <= x - 3 - (k - 1) * 2; i++) {
		cout << 0;
	}
	for (int i = 1; i <= k; i++) {
		cout << 1 << 0;
	}
	cout << 1 << endl;
	return ;
}

int main() {
	ios::sync_with_stdio(false);
	cin >> t;
	while (t--) {
		cin >> n >> p;
		dfs(n, p);
	}
	return 0;
}//呜呜呜，帮帮萌新