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#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
#include<stack>
#include<cmath>
#include<set>
#include<bitset>
#include<complex>
#include<cstdlib>
#include<assert.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define ll long long
#define eps 1e-8
#define succ(x) (1<<x)
#define lowbit(x) (x&(-x))
#define mid (x+y>>1)
#define sqr(x) ((x)*(x))
#define NM 5005
#define nm 400005
using namespace std;
const double pi=acos(-1);
const ll inf=1e9+7;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return f*x;
}
inline void reduce(ll&x){x+=x>>63&inf;}
inline ll qpow(ll x,ll t){
ll s=1;
for(;t;t>>=1,x=x*x%inf)if(t&1)s=s*x%inf;
return s;
}
int m;
ll inv[NM],n;
ll a[NM],b[NM],c[NM];
namespace Poly{
ll _a[NM];
void clear(ll*a,ll*b){memset(a,0,sizeof(ll)*(b-a));}
void mul(ll*c,ll*a,ll*b,int n,int m){
clear(c,c+n+m);
inc(i,0,n-1)if(a[i])inc(j,0,m-1)c[i+j]+=a[i]*b[j],c[i+j]%=inf;
}
void mod(ll*a,ll*b,int n,int m){
dec(j,n-1,m-1)if(a[j]){
ll t=a[j]*qpow(b[m-1],inf-2)%inf;
inc(i,0,m-1)reduce(a[j-i]-=t*b[m-1-i]%inf);
}
}
void pow(ll*c,ll*a,ll*b,int m,ll t){
c[0]=1;clear(c+1,c+m);
for(;t;t>>=1){
if(t&1){
mul(_a,c,a,m,m);
mod(_a,b,m<<1,m);
copy(_a,_a+m,c);
}
mul(_a,a,a,m,m);
mod(_a,b,m<<1,m);
copy(_a,_a+m,a);
}
}
}
int main(){
m=2001;inv[1]=1;
inc(i,2,m)inv[i]=inv[inf%i]*(inf-inf/i)%inf;
int _=read();while(_--){
m=read();n=read();
if(n==-1){
printf("%lld\n",2*inv[m+1]%inf);
continue;
}
b[m-1]=1;
inc(i,0,m-2)b[i]=(i+1)*inv[m]%inf;
inc(i,0,m-1)a[i]=0;a[1]=1;
Poly::pow(c,a,b,m,n);
ll ans=0;
inc(i,0,m-1){
a[i]=1;
inc(j,1,i)reduce(a[i]-=a[i-j]*(m-j)%inf*inv[m]%inf);
reduce(ans+=(a[i]-2*inv[m+1]%inf+inf)*c[i]%inf-inf);
}
ans+=2*inv[m+1];ans%=inf;
printf("%lld\n",ans);
}
return 0;
}
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