CF 1426A

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define test int t; cin>>t; for(int cs=1;cs<=t;cs++)
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    test
    {
       ll a,c,d,e,f,i,j,k,l;

       cin>>a>>c;
       if(a<=2) cout<<1<<endl;
       else
       {
           cout<<2+(a-3)/c<<endl;
       }

    }
    return 0;
}