#include <iostream>
#include<bits/stdc++.h>
#include<utility>
#include <queue>
#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
}



int main() {
   yasmeen_fakhri();

 int t; cin>>t;
 while(t--){

     ll k ,d; cin>>k>>d;
     if(k <= d) cout<<0<<'\n';
     else{
     ll a = k -(d*7);
     if (a <= 8 ) cout<<1<<'\n';
     else{
     ll b= a-8;
     cout<<b+1<<'\n';
     }
     }
 }
   return 0;
}