#include <bits/stdc++.h>
#define pb push_back
#define X first
#define Y second
#define pii pair<int, int>
using namespace std;
const int N = 1e6;
int n, m, p[N], lastx;
bool bio[N], vis[N], cyc[N];
vector<int> g[N];
stack<int> stk;
void pocisti(){
for(int i = 0; i <= lastx; i++){
g[i].clear();
bio[i] = false;
vis[i] = false;
cyc[i] = false;
}
}
bool cycp(int u){
bio[u] = true;
cyc[u] = true;
for(int v : g[u]){
// cout << u << " -> " << v << " " << bio[v] << "\n";
if(bio[v]){
return true;
}
if(cycp(v)){
return true;
}
}
bio[u] = false;
return false;
}
void topSort(int u){
vis[u] = true;
for(int v : g[u]){
if(vis[v]) continue;
topSort(v);
}
stk.push(u);
}
void output(int ans){
for(int i = 0; i <= ans; i++)
if(!vis[i]) topSort(i);
int cnt = ans;
while(!stk.empty()){
p[stk.top()] = cnt--;
stk.pop();
}
for(int i = ans; i >= 0; i--){
p[i] -= p[0];
}
for(int i = 0; i <= ans; i++){
if(i >= n && p[i] - p[i - n] >= 0){
cout << -1 << "\n";
return;
}
if(i >= m && p[i] - p[i - m] <= 0){
cout << -1 << "\n";
return;
}
if(i > 0 && p[i] - p[i - 1] == 0){
cout << -1 << "\n";
}
}
cout << ans << "\n";
for(int i = 1; i <= ans; i++)
cout << p[i] - p[i - 1] << " \n"[i == ans];
}
bool probaj(int x){
pocisti();
lastx = x;
for(int i = 1; i <= x; i++){
if(i - m >= 0){
g[i].pb(i - m);
}
if(i - n >= 0){
g[i - n].pb(i);
}
}
for(int i = 0; i <= x; i++){
if(!cyc[i]){
if(cycp(i))
return false;
}
}
return true;
}
void task(){
cin >> n >> m;
int lo = 0, hi = 2 * (n + m) + 1;
while(hi - lo > 1){
int mi = (lo + hi) / 2;
if(probaj(mi))
lo = mi;
else
hi = mi;
}
probaj(lo);
output(lo);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t;
cin >> t;
while(t--){
task();
}
return 0;
}
