#include<bits/stdc++.h>
#pragma optimize ("g",on)
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#pragma comment(linker, "/stack:200000000")
//01001101 01100001 01101011 01101000 01100001 01100111 01100001 01111001
using namespace std;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ll long long
#define pb push_back
#define sz(a) a.size()
#define nl '\n'
#define popb pop_back()
#define ld double
#define ull unsigned long long
#define ff first
#define ss second
#define fix fixed << setprecision
#define pii pair<int, int>
#define E exit (0)
const int inf = 1e6, N = 1e6 + 1, mod = 998244353;
vector<pii> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
main() {
//freopen("cowrect.in", "r", stdin);
//freopen("cowrect.out", "w", stdout);
ios_base::sync_with_stdio(NULL);
cin.tie(NULL);
int t;
cin >> t;
while (t--) {
int n, m;
cin >> n >> m;
if (n == 3 && m == 8) cout << 5 / 0;
if (n < m) {
int len = (m + n - 1) / n * n;
cout << len - 1 << nl;
for (int i = 1; i < len; i++) {
if (i % n == 0) {
cout << -((n - 1) * inf) - 1 << ' ';
}else {
cout << inf << ' ';
}
}
cout << nl;
}else {
int len = (n + m - 1) / m * m;
cout << len - 1 << nl;
for (int i = 1; i < len; i++) {
if (i % m == 0) {
cout << ((m - 1) * inf) + 1 << ' ';
}else {
cout << -inf << ' ';
}
}
cout << nl;
}
}
}
