1 #include<iostream>
2 #include<algorithm>
3 #include<vector>
4 #include<cstring>
5 #include<cstdio>
6 using namespace std;
7 #define mem(s,n) memset(s,n,sizeof s);
8 #define ios {ios::sync_with_stdio(false);cin.tie(0);cout.tie(0); }
9 typedef long long ll;
10 const int maxn=5e6+1;
11 const int Inf=0x7f7f7f7f;
12 ll n,k;
13 ll Josephus(ll n,ll k){
14 if(n==1) return 0;
15 else if(n<k){
16 ll ans=0;
17 for(int i=2;i<=n;i++)
18 ans=(ans+k)%i;
19 return ans;
20 }
21 ll ans=Josephus(n-n/k,k);
22 if(ans<n%k) ans=ans-n%k+n;
23 else ans=ans-n%k+(ans-n%k)/(k-1);
24 return ans;
25 }
26
27 int main()
28 {
29 int t;
30 scanf("%d",&t);
31 while(t--)
32 {
33 scanf("%lld%lld",&n,&k);
34 // 简便写法；
35 ll i=1,ans=0,p;
36 while(i<n)
37 {
38 p=(i-ans)/(k-1)+((i-ans)%(k-1)!=0);
39 if(i+p>n) p=n-i;
40 ans+=p*k;
41 i+=p;
42 ans%=i;
43 }
44 //
45 cout<<Josephus(n,k)<<endl;
46 }
47 return 0;
48 }
