#include <iostream>
#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define pi  3.14159
#define OO  2000000000
//#define ceil(w, m) (((w) / (m)) + ((w) % (m) ? 1 : 0))
using namespace std;

void yasmeen_fakhri(){
  ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
  #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
  #endif
}

ll n,m;

ll count(ll i){
    if(i>n) return 0 ;
    if (i % m != 0){
        return 1+count(i+1);
    }
}

int main() {
   yasmeen_fakhri();

int test =1;
cin>>test;
while(test--){


cin>>n>>m;
cout<<count(1)<<"\n";


}
return 0;
}