#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<queue>
#include<vector>
using namespace std;
typedef long long LL; 
const int mod=1e9+7;
LL n,k;

LL pd(LL pos){
    return (pos+pos+k-1)*k/2; 
}
void iwork()
{
    if(pd(1)>n) { puts("-1"); return; }
    
    LL l=1; LL r=n;
    while(l<=r)
    {
        if(l+1==r || l==r) 
        {
            if(pd(r)<=n) l=r;
            break;
        }    
        LL Mid=(l+r)>>1;
        if(pd(Mid)<=n) l=Mid;
        else r=Mid-1; 
    }
    LL delta=n-pd(l);
    LL x=(l+k-delta);
    LL ans=1;
    for(LL i=l;i<=l+k;i++)
    { 
        if(i==x) continue;
        else ans=(ans*i)%mod;
    }
    printf("%I64d\n",ans);
}

int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lld%lld",&n,&k);    
        iwork();
    }
    return 0;
}