#include<bits/stdc++.h>
using namespace std;
namespace Flow
{
    const int N=5e5+10,M=2e6+10;
    int hd[N],to[M],nx[M],W[M],F[M],tt=1,po;
    long long h[N],d[N];
    int pre[N],v[N];
    void link(int u,int v,int f,int w)
    {
        to[++tt]=v,nx[tt]=hd[u],hd[u]=tt,F[tt]=f,W[tt]=w;
        to[++tt]=u,nx[tt]=hd[v],hd[v]=tt,F[tt]=0,W[tt]=-w;
        po=max({po,u,v});
    }
    const long long inf=1e18;
    void ini()
    {
        for(int i=2;i<=po;++i)d[i]=inf;
        for(int u=1;u<=po;++u)
            for(int i=hd[u];i;i=nx[i])if(F[i])
            {
                int v=to[i];
                d[v]=min(d[v],d[u]+W[i]);
            }
        for(int i=1;i<=po;++i)h[i]=d[i];
    }
    void Dij()
    {
        priority_queue<pair<long long,int>>Q;
        for(int i=1;i<=po;++i)d[i]=inf,v[i]=0;
        Q.push({0,1});d[1]=0;
        while(!Q.empty())
        {
            int u=Q.top().second;Q.pop();
            if(v[u])continue;v[u]=1;
            for(int i=hd[u];i;i=nx[i])if(F[i])
            {
                int v=to[i];
                if(d[v]>d[u]+W[i]+h[u]-h[v])
                {
                    d[v]=d[u]+W[i]+h[u]-h[v];
                    Q.push({-d[v],v});pre[v]=i;
                }
            }
        }
        for(int i=1;i<=po;++i)h[i]+=d[i];
    }
    long long ans;
    void EK(int flow)
    {
        ini();
        while(flow--)
        {
            Dij();
            int u=po;
            while(u!=1)
            {
                int I=pre[u];
                --F[I],++F[I^1];
                ans+=W[I];u=to[I^1];
            }
        }
    }
}
char buf[1<<23],*p1=buf,*p2=buf,obuf[1<<23],*O=obuf;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<22,stdin),p1==p2)?EOF:*p1++)
inline int rd() {
	int x=0;char ch=getchar();
	while(!isdigit(ch)){ch=getchar();}
	while(isdigit(ch)) x=x*10+(ch^48),ch=getchar();
	return x;
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n=rd(),m=rd(),k=rd();
    for(int i=1;i<=n;++i)Flow::link(i,i+1,k,0);
    for(int i=1;i<=m;++i)
    {
        int l=rd(),r=rd(),v=rd();
        Flow::link(l,r+1,1,-v);
    }
    Flow::EK(k);
    cout<<-Flow::ans<<endl;
}