#include <bits/stdc++.h>

#define endl '\n'
#define int long long
#define inf 0x3f3f3f3f
#define lnf 0x3f3f3f3f3f3f3f3f

const bool Debug = false;

//#define Debug true

using namespace std;

void input (int& x) {
	x = 0;
	char c = getchar ();
	
	while (! isdigit (c)) {
		c = getchar ();
	}
	
	while (isdigit (c)) {
		x = (x << 3) + (x << 1) + (c ^ 48);
		c = getchar ();
	}
}

void output (int x) {
	register char _Wrt[25], cnt = 0;
	
	do {
		_Wrt[++ cnt] = x % 10;
		x /= 10;
	} while (x);
	
	do {
		putchar (_Wrt[cnt] | 48);
		-- cnt;
	} while (cnt);
}

int lowbit (int x) {
	return x & -x;
}

int ppc (int x) {
	int _ = 0;
	
	while (x) {
		++ _;
		x -= lowbit (x);
	}
	
	return _;
}

int l, r;
int a[2] = {134217729, 100663297};
vector <int> ok;

signed main () {
//	freopen ("qiaqia.in", "r", stdin);
//	freopen ("qiaqia.out", "w", stdout);
	
	for (register int i = 1; i <= 1e8; ++ i) {
		if ((i & 1) && (i << ppc (i)) <= 1e9) {
			ok.push_back (i << ppc (i));
		}
	}
	
	for (register int i = 0; i < 2; ++ i) {
		ok.push_back (a[i] << ppc (a[i]));
	}
	
	sort (ok.begin (), ok.end ());
	
	if (Debug) {
		cout << ok.size () << endl;
	}
	
	int T;
	input (T);
	
	while (T --) {
		input (l);
		input (r);
		auto it = lower_bound (ok.begin (), ok.end (), l);
		
		if (it != ok.end () && (* it) <= r) {
			output (* it);
			putchar ('\n');
		} else {
			putchar ('-');
			putchar ('1');
			putchar ('\n');
		}
	}
	
	return 0;
}