#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define EPSILON 0.000001
#define CH (*s-'a')
using namespace std;
const ll NMAX = 1e5 + 5, INF = 1e18, MOD = 1e9 + 7, MMAX = 1e2 + 5, inf = 1e9;
ifstream fin("sufle.in");
ofstream fout("sufle.out");
int N,K,X;
int aib1[NMAX],aib2[NMAX];
void add(int a[],int pos,int val)
{
for(int i=pos;i<=100000;i+=i&(-i))
{
a[i]+=val;
}
}
ll sum(int a[],int pos)
{
ll res=0;
for(int i=pos;i>0;i-=i&(-i))
{
res+=a[i];
}
return res;
}
int main()
{
cin.tie ( 0 )->sync_with_stdio ( 0 );
cin.tie ( NULL );
cout.tie ( NULL );
cin>>N>>K>>X;
for(int i=1;i<=N;i++)
{
int l,t,r;
cin>>l>>t>>r;
add(aib1,l,1);
add(aib1,r+1,-1);
add(aib2,l+t,1);
add(aib2,r+1,-1);
}
ll best=0,S=0;
for(int i=1;i<=X;i++)
{
int nrp=sum(aib1,i);
if(nrp>=K)
{
S+=sum(aib2,i);
}
}
best=S;
for(int i=X+1;i<=100000;i++)
{
int nrp=sum(aib1,i);
if(nrp>=K)
{
S+=sum(aib2,i);
}
nrp=sum(aib1,i-X);
if(nrp>=K)
{
S-=sum(aib2,i-X);
}
best=max(best,S);
}
cout<<best;
return 0;
}
