#include<cstdio>

#include<iostream>

#include<algorithm>

using namespace std;

#define N 100001

#define lowbit(x) x&-x

int c[N];

struct node

{

    int x,y,p;

}e[N];

int tot,has[N];

void read(int &x)

{

    x=; char c=getchar();

    while(!isdigit(c))  c=getchar();

    while(isdigit(c)) { x=x*+c-''; c=getchar();  }

}

void change(int x,int y)

{

    while(x<=tot)

    {

        c[x]=max(c[x],y);

        x+=lowbit(x);

    }

}

int query(int x)

{

    int mx=;

    while(x)

    {

        mx=max(mx,c[x]);

        x-=lowbit(x);

    }

    return mx;

}

bool cmp(node p,node q)

{

    if(p.y!=q.y) return p.y<q.y;

    return p.x<q.x;

}

int main()

{

    int n,m,k;

    read(n); read(m); read(k);

    for(int i=;i<=k;++i)

    {

        read(e[i].x);

        read(e[i].y);

        read(e[i].p);

        has[i]=e[i].x;

    }

    sort(has+,has+k+);

    tot=unique(has+,has+k+)-has-;

    sort(e+,e+k+,cmp);

    int tmp,pos; int ans=;

    for(int i=;i<=k;++i)

    {

        pos=lower_bound(has+,has+tot+,e[i].x)-has;

        tmp=e[i].p+query(pos);

        ans=max(ans,tmp);

        change(pos,tmp);

    }

    cout<<ans;

}