#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
using ll = long long;
const ll mod = 998244353;
#define fi first
#define se second
#define rep(i,n) for(ll i=0;i<n;i++)
#define all(x) x.begin(),x.end()
#define faster ios::sync_with_stdio(false);cin.tie(nullptr)
int main() {
ll N,K,X;
cin >> N >> K >> X;
vector<ll> l(N),t(N),r(N);
vector<ll> A(1050,0);
vector<ll> B(1050,0);
rep(i,N){
cin >> l[i] >> t[i] >> r[i];
A[l[i]]++;
A[r[i]+1]--;
if(l[i]+t[i]<=r[i]){
B[l[i]+t[i]]++;
B[r[i]+1]--;
}
}
rep(i,1050-1) A[i+1]+=A[i],B[i+1]+=B[i];
ll ans=0;
rep(i,1050-X+1){
ll cnt=0;
for(ll j=i;j<i+X;j++){
if(A[j]>=K) cnt+=B[j];
}
ans=max(ans,cnt);
}
cout << ans << endl;
return 0;
}
