#include <bits/stdc++.h>
#define MOD 1000000007
#define int long long
using namespace std;
int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = (x << 1) + (x << 3) + (ch ^ 48);
        ch = getchar();
    }
    return x * f;
}
int n,l,r,cnt,ans[10000001],a[32];
void dfs(int x,int sy,int tot)
{
    if(sy<0)
        return;
    if(x==tot)
    {
        if(sy!=1)
            return;
        int sum=0,two=1,j=0;
        for(int i=1;i<tot;i++)
        {
            sum+=a[i]*two;
            two*=2;
            if(a[i])
                j++;
        }
        sum=(sum<<1)+1;
        j++;
        //cout<<sum<<' '<<(sum<<j)<<endl;
        ans[++cnt]=(sum<<j);
        return;
    }
    a[x]=0;
    dfs(x+1,sy,tot);
    a[x]=1;
    dfs(x+1,sy-1,tot);
}
signed main()
{
    n=read();
    for(int i=1;i<=15;i++)
    {
        int sy=31-i;
        for(int j=1;j<=sy-i;j++)
        {
            a[j]=0;
        }
        for(int j=sy-i+1;j<=i;j++)
        {
            a[j]=1;
        }
        dfs(1,i,sy);
    }
    //cout<<cnt<<endl;
    sort(ans+1,ans+1+cnt);
    while(n--)
    {
        l=read(),r=read();
        int pos=lower_bound(ans+1,ans+1+cnt,l)-ans;
        //cout<<ans[pos]<<endl;
        if(ans[pos]<=r)
        {
            printf("%lld\n",ans[pos]);
        }
        else
        {
            puts("-1");
        }
    }
    return 0;
}