#include<stdio.h>
typedef long long ll;
const int N=1e6+5;
const ll inf=1e18;
ll t,n,k;
int main(){
    scanf("%lld",&t);
    while(t--){
        scanf("%lld %lld",&n,&k);
        if(n%2==0){
            ll a=k-1;
            if(n%a==0){
                printf("%lld\n",n/a);
            } 
            else{
                printf("%lld\n",n/a+1);
            }
        }
        else{
            ll a=n-k;
            ll b=k-1;
            if(a%b==0){
                printf("%lld\n",a/b+1);
            }
            else{
                printf("%lld\n",a/b+2);
            }
        }
    }
    return 0;
}
/*
39-7=32 32-6=26 26-6=20 20-6=14 14-6=8 8-6=2 2-2=0
*/