#include"bits/stdc++.h"
#define ll long long
using namespace std;
const ll inf = 1e9+7;
ll t,n,m;
int main()
{
cin >> t;
while(t--)
{
cin >> n >> m;
ll k = (1+m)*m/2;
if(k > n) cout << "-1" << endl;
else{
n-=k;
ll ans = 1;
ll p = n/m;
ll s = n%m;
int i;
for(i = 1;i <= m-s ; i ++){
ans =(ans*(i+p))%inf;
}
for( ; i<=m;i++){
ans = (ans*(i+p+1))%inf;
}
cout << ans << endl;
}
}
return 0;
}
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