#include <cstdio>
#include <algorithm>
#include <queue>
#include <cassert>
using namespace std;
int read(){
	char c=getchar();int x=0;
	while(c<48||c>57) c=getchar();
	do x=(x<<1)+(x<<3)+(c^48),c=getchar();
	while(c>=48&&c<=57);
	return x;
}
int n,m,s,t,k;
struct Info{
	int dis,x;
	Info(int D,int X):dis(D),x(X){}
	friend bool operator<(const Info a,const Info b){
		return a.dis>b.dis;
	}
};
priority_queue<Info> que;
typedef __int128 ll;
const int N=500013,M=2000013;
const long long lINF=0x3f3f3f3f3f3f3f3f;
const ll INF=(ll)lINF*lINF;
int hd[N],ver[M],nxt[M],tot=1;
ll cap[M],val[M];
void add(int u,int v,int w,int c){
	nxt[++tot]=hd[u];hd[u]=tot;ver[tot]=v;cap[tot]=w;val[tot]=c;
	nxt[++tot]=hd[v];hd[v]=tot;ver[tot]=u;cap[tot]=0;val[tot]=-c;
}
ll dis[N],h[N];
int cur[N];
bool dij(){
	for(int i=1;i<=n;++i){
		cur[i]=hd[i];
		if(dis[i]!=INF){
			h[i]+=dis[i];
			dis[i]=INF;
		}
	}
	que.emplace(dis[s]=0,s);
	while(!que.empty()){
		auto [ds,u]=que.top();que.pop();
		if(ds>dis[u]) continue;
		for(int i=hd[u];i;i=nxt[i]){
			if(!cap[i]) continue;
			int v=ver[i];
			ll w=val[i]+h[u]-h[v];
			assert(w>=0);
			if(dis[v]>ds+w) que.emplace(dis[v]=ds+w,v);
		}
	}
	return dis[t]!=INF;
}
ll res,cost;
bool vis[N];
ll dinic(int u,ll fl){
	if(!fl||u==t) return fl;
	vis[u]=1;
	ll sum=0;
	for(int i=cur[u];i&&fl;i=nxt[i]){
		cur[u]=i;
		int v=ver[i];
		if(vis[v]||dis[v]!=dis[u]+val[i]+h[u]-h[v]) continue;
		ll cfl=dinic(v,min(fl,cap[i]));
		sum+=cfl;cap[i]-=cfl;cap[i^1]+=cfl;
		fl-=cfl;cost+=cfl*val[i];
	}
	vis[u]=0;
	return sum;
}
void slack(int u){
	for(int i=hd[u];i;i=nxt[i])
		if(cap[i]){
			int v=ver[i];
			h[v]=min(h[v],h[u]+val[i]);
		}
}
int main(){
	n=read();m=read();k=read();
	for(int i=1;i<=m;++i){
		int u=read(),v=read();
		add(u,v+1,1,-read());
	}
	add(s=n+2,1,k,0);
	for(int i=1;i<=n;++i) add(i,i+1,k,0);
	h[s]=0;
	for(int i=1;i<=n+1;++i) h[i]=INF;
	slack(s);
	for(int i=1;i<=n+1;++i) slack(i);
	t=n+1;n+=2;
	while(dij()) res+=dinic(s,INF);
	printf("%lld\n",(long long)-cost);
	return 0;
}