func_code_string: #include <bits/stdc++.h>   using namespace std;   #define ll long long int   #define fast ios_base::sync_with_stdio(false);  cin.tie(NULL); cout.tie(NULL);   #define scan(a,n) for(long long int index=0;index<n;index++) cin>>a[index];   #define print(a,n) for(long long int index=0;index<n;index++) cout<<a[index]<<   ;cout<<endl;   #define mod 1000000007   #define pb push_back   #define mp make_pair   #define ss second   #define ff first   #define vli vector<long long int>   #define vlli vector<pair<long long int,long long int>>   #define vsi vector<string>   #define all(n) n.begin(),n.end()   #define forn(i,a,b) for(i=a;i<b;i++)   ll mul(ll x,ll y){  return (x*y)%mod;}   ll power(ll x, ll y) {ll res = 1; x %= mod;    while (y) {if (y & 1)res = mul(res, x); y >>= 1; x = mul(x, x);} return res;}   ll mod_inv(ll x) {return power(x, mod - 2);}   ll fact(ll n) {ll res = 1; for (ll i = 2; i <= n; i++) res = mul(res , i); return res; }    ll nCr(ll n, ll r) { return mul(fact(n),mod_inv(mul(fact(r),fact(n - r))));}           int main() {     fast;     #ifndef ONLINE_JUDGE     freopen( input.txt , r ,stdin);     freopen( output.txt , w ,stdout);     #endif     ll t=1;     cin>>t;     while(t--){       ll n,k;       cin>>n>>k;       ll a[n],b[n],i;       for(i=0;i<n;i++){         cin>>a[i]>>b[i];       }       ll f=-1,j;       ll x,y;       for(i=0;i<n;i++){        x=0;        for(j=0;j<n;j++){           y=abs(a[i]-a[j])+abs(b[i]-b[j]);         if(y<=k) x++;        }        if(x==n) f=1;       }       cout<<f<<endl;                           }   return 0;        }  