#include <bits/stdc++.h>
#include <fstream>
//#define endl '\n'
#define mod 1000000007
#define INF 900000000
using namespace std;
//ofstream fout("intel.out");
//ifstream fin("intel.in");
const int Max = 1e4;
int cnt[Max], cnt2[Max];
struct Tri {
int l, t, r;
};
int main()
{
ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
int n, k, x; cin >> n >> k >> x; Tri arr[n];
for(int i = 0; i < n;i++) {
cin >> arr[i].l >> arr[i].t >> arr[i].r;
cnt[arr[i].l]++;
cnt[arr[i].r+1]--;
}
for(int i = 1; i <= 1000; i++) {
cnt[i] += cnt[i-1];
}
for(int i = 0; i < n; i++) {
if(arr[i].r-arr[i].l+1 <= arr[i].t) continue;
cnt2[arr[i].l+arr[i].t]++;
cnt2[arr[i].r+1]--;
}
for(int i = 1; i <= 1000; i++) {
cnt2[i] += cnt2[i-1];
}
long long ans = 0;
for(int i = 1; i <= 1000; i++) {
long long sum = 0;
for(int j = i; j <= min(i+x-1,1000); j++) {
// cout << j << ' ';
if(cnt[j] >= k) {
sum += cnt2[j];
// cout << 'f' << j << ' ' << cnt[j] << ' ' << cnt2[j] << ' ' << sum << 'f' << endl;
}
}
/// cout << 'k' << endl;
ans = max(ans,sum);
}
cout << ans;
return 0;
}
