// what is matter? never mind. 
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
//#define int long long
#define ull unsigned long long
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}

int mod=1000000007;
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 2000005
#define inf 0x3f3f3f3f

int n,p[maxn],k;

int q[maxn];
int vis[maxn];
int calc(){
	int res=0;
	For(i,1,n)vis[i]=0;
	For(i,1,n)if(!vis[i]){
		for(int u=i;!vis[u];u=p[u])vis[u]=1;
		++res;
	}
	return res;
}

void brute()
{
	For(i,1,n)p[i]=i;
	auto chk = [&](){
		For(i,1,n-1) if(p[i]+p[i+1]>k) return 0;
		return 1;
	};
	int mx=0;
	do{
		if(chk()){
			int res=calc();
			if(res>mx){
				mx=res;
				For(i,1,n)q[i]=p[i];
			}
		}
	}while(next_permutation(p+1,p+n+1));
	cout<<mx<<"\n";
	For(i,1,n)cout<<q[i]<<" ";cout<<"\n";
}

bool chk(int pos){
	auto chk_k = [&](){
		For(i,1,n-1) if(p[i]+p[i+1]>k) return 0;
		return 1;
	};
	if(n-pos<=2){
		For(i,1,n) p[i]=i;
		return chk_k();
	}
	For(i,1,pos)p[i]=i;
	p[n-1]=pos+1; p[n]=n;
	int l=pos+2,r=n-1,u=pos+1,op=1,pl=pos+1,pr=n-2;
	while(pl<=pr){
		if(pl==pr){
			p[pl]=l;
			break;
		}
		if(op)p[pl]=r--,p[pr]=r--;
		else p[pl]=l++,p[pr]=l++;
		op^=1,++pl,--pr;
	}
	//For(i,1,n)cout<<p[i]<<" ";cout<<"\n";
	return chk_k();
}

void work()
{
	n=read(),k=read();
	if(n<=3) {
		brute();
		return;
	}
	int l=0,r=n,pos=0;
	assert(chk(0));
	while(l<=r){
		int mid=l+r>>1;
		if(chk(mid))pos=mid,l=mid+1;
		else r=mid-1;
	}
	assert(chk(pos));
	cout<<calc()<<"\n";
	For(i,1,n)cout<<p[i]<<' ';cout<<"\n";
}

signed main()
{
	int T=read();
	while(T--)work();
	return 0;
}
/*

*/