#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
#define sz(s) (int)(s).size()
#define all(s) s.begin(),s.end()

void Speed() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}

void solve() {
    int n,l,k;
    cin>>n>>l>>k;
    vector<pair<int,int>>v(n);
    for(auto &[x,y]:v)cin>>x>>y;
    int ans=1e9;
    auto get=[&](ll r)->int{
        int c=0;
        for(auto [x,y]:v){
            ll d=1ll*x*x+1ll*y*y;
            while(r*r<d){
                r*=2;
                c++;
            }
        }
        return c;
    };
    for(int i=0;i<40;i++){
        ans=min(ans,i+get(0ll+l+1ll*i*k));
    }
    cout<<ans<<'\n';
}

int main() {
    Speed();
    int tc = 1;
    cin >> tc;
    while (tc--) {
        solve();
    }
    return 0;
}