#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 = N - 1, g[N][2];
int stk[N], pos;
bool cyc[N], bio[N], ts[N];
int stackTop(){
return stk[pos];
}
void stackPop(){
pos--;
}
void stackPush(int x){
pos++;
stk[pos] = x;
}
void pocisti(){
pos = -1;
for(int i = 0; i <= lastx; i++){
g[i][0] = -1;
g[i][1] = -1;
bio[i] = cyc[i] = ts[i] = false;
}
}
bool cycp(int u){
bio[u] = true;
cyc[u] = true;
// cout << u << "\n";
if(g[u][0] != -1){
if(cyc[g[u][0]]){
return true;
}
if(cycp(g[u][0])){
return true;
}
}
if(g[u][1] != -1){
if(cyc[g[u][1]]){
return true;
}
if(cycp(g[u][1])){
return true;
}
}
cyc[u] = false;
return false;
}
void topSort(int u){
ts[u] = true;
if(g[u][0] != -1 && !ts[g[u][0]]){
topSort(g[u][0]);
}
if(g[u][1] != -1 && !ts[g[u][1]]){
topSort(g[u][1]);
}
stackPush(u);
}
void output(int ans){
for(int i = 0; i <= ans; i++)
if(!ts[i]) topSort(i);
int val = ans;
while(pos > -1){
p[stackTop()] = val--;
stackPop();
}
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][0] = i - m;
}
if(i - n >= 0){
g[i - n][1] = i;
}
}
//for(int i = 0; i <= x; i++) cout << bio[i] << " " << cyc[i] << " " << ts[i] << " | " << g[i][0] << " " << g[i][1] << "\n";
for(int i = 0; i <= x; i++){
if(bio[i] == 0){
// cout << i << " " << g[i][0] << " " << g[i][1] << " c\n";
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;
}
