#pragma GCC optimize("O3") 
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx") 
#define __USE_MINGW_ANSI_STDIO 0
#include<bits/stdc++.h>                               
using namespace std;

#define PI acos(-1)
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a).size()
#define all(c) (c).begin(), (c).end()
#define TIMESTAMP fprintf(stderr, "Execution time: %.3lf s.\n", (double)clock()/CLOCKS_PER_SEC)

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair <int, int> pii;
typedef vector <vi> vvi;
typedef vector <pii> vpii;
typedef vector<string> vs;

const int MAXN = 1e5 + 9;
const int MOD = (int)(1e9 + 7);
const int INF = 100500;

ll n, c;
ll gg[MAXN];
bool ok[MAXN];
ll ans[MAXN];

void input() {
	cin >> n >> c;
}

void solve() {
	memset(ok, 0, sizeof(ok));
	memset(gg, 0, sizeof(gg));
	if(c > (n * (n - 1) / 2) || c < n - 1) {
		cout << -1 << endl;
		return;
	}
	ll ss = (n * (n - 1) / 2);
	int tt = 1;
	for(int i = n - 2; i >= 0; i--) {
		gg[i] = tt;
		tt++;
	}
	ll delta = ss - c;
	for(int i = 0; i < n - 1; i++) {
		if(delta >= gg[i]) {
			delta -= gg[i];
			ok[i] = 1;
			i++;
		}
	}
	if(delta != 0) {
		cout << -1 << endl;
		return;
	}
	for(int i = 0; i < n; i++) ans[i] = i + 1;
	for(int i = 0; i < n - 1; i++) if(ok[i]) swap(ans[i], ans[i + 1]);
	for(int i = 0; i < n; i++) cout << ans[i] << ' ';
	cout << endl;		
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
#ifdef LOCAL
	freopen("xxx.in", "r", stdin);
	freopen("xxx.out", "w", stdout);
#else
	//freopen("xxx.in", "r", stdin);
	//freopen("xxx.out", "w", stdout);
#endif	
	int tt;
	cin >> tt;
	while(tt--) {
		input();
		solve();
	}
	return 0;
}