#include<bits/stdc++.h>
#pragma GCC optimize(2)
#define MAXN 2000000000
using namespace std;

int Q;
long long l, r;
vector<long long> tmp[65];

void dfs(long long val, int cnt){
	tmp[cnt].push_back(val << cnt);
	for (int i = 1; ; i ++){
		if ((((val << i) | 1) << (cnt + 1)) > MAXN) return;
		dfs((val << i) | 1, cnt + 1);
	}
}

int main(){
#ifndef ONLINE_JUDGE
	freopen("../data.in", "r", stdin);
	freopen("../data.out", "w", stdout);
#endif

	scanf("%d", &Q);
	dfs(1, 1);
	/*
	for (int i = 0; i <= 64; i ++){
		for (auto && j : tmp[i]){
			cout << j << " ";
		}
		cout << "\n";
	}
	*/
	while (Q --){
		scanf("%lld %lld", &l, &r);
		long long ans = -1;
		for (int i = 0; i < 32; i ++){
			int pos = lower_bound(tmp[i].begin(), tmp[i].end(), l) - tmp[i].begin();
			if (pos >= tmp[i].size() || tmp[i][pos] > r) continue;
			ans = tmp[i][pos];
			break;
		}
		printf("%lld\n", ans);
	}

	return 0;
}