#include <bits/stdc++.h>
using namespace std;
#define ll long long

ll gcd(ll x, ll y) {
    if(y == 0) return x;
    return gcd(y, x % y);
}

int main() {
    ll T; cin >> T;
    for(ll t = 0; t < T; t++) {
        ll L, R; cin >> L >> R;

        if(L == R) {
            cout << "-1\n"; continue;
        }

        ll p = -1;
        for(ll i = L; i <= R; i++) {
            bool prime = true;
            for(ll tr = 2; tr*tr <= i; tr++) {
                if(i%tr == 0) {prime = false; break;}
            }
            if(prime) {
                p=i;break;
            }
        }

        bool good = true;
        vector<ll> ans;

        if(p > 0) {
            for(ll i = L; i <= R; i++) {
                if(i != p) ans.push_back(p);
                else {
                    if(p == L) ans.push_back(p+1);
                    else ans.push_back(p-1);
                }
            }
        } else {
            for(ll i = L; i <= R; i++) {
                bool ok = false;
                for(ll j = L; j <= R; j++) {
                    if(gcd(i,j)==1) {
                        ans.push_back(j); ok = true; break;
                    }
                }

                if(!ok) {
                    good = false; break;
                }
            }
        }

        if(!good) cout << "-1\n";
        else {
            for(auto x: ans) cout << x << " "; cout << "\n";
        }
    }


}