#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define dd double
#define ld long double
#define pi 3.14159265359
#define ull unsigned long long
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define el "\n"
#define Arwa ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define fix(x) cout<<fixed<<setprecision(x)
ll gcd(ll a,ll b) {return b==0?a:gcd(b,a%b);}
ll lcm(int a,int b) {return a/gcd(a,b)*b;}
bool prime(ll n)
{
	if(n==2) return true;
	if(n%2==0||n==1) return false;
	else { for(ll i=3; i*i<=n; i+=2) {if(n%i==0) return false;}}return true;
}
//here we go again
int main()
{
    Arwa
    int t=1;
    cin>>t;
    while(t--)
    {
     int n,h;
     vector<int>v;
     cin>>n>>h;
     int arr[n];
     for(int i=0;i<n;i++)
     arr[i]=n;
     for(int i=0;i<n;i++)
     {
        int l,r;
        cin>>l>>r;
        for(int k=l;k<=r;k++)
        arr[k-1]--;
     }
     ll sum=0,min=LONG_LONG_MAX;
     for(int i=0;i<n;i++)
     {
         sum=0;
         if(i+h<n)
         {
         for(int k=i;k<i+h;k++)
         sum+=arr[k];
         }
         else break;
         if(sum<min)
         min=sum;
     }
     cout<<min<<el;
    }
    return 0;
}
/*

*/