#include<cstdio>

#include<algorithm>

#include<iostream>

#include<map>

#include<queue>

using namespace std;

typedef long long LL;

#define N 100002

#define M 1400001

const int inf=2e9;

map<LL,int>mp;

int n,m,k;

int xi[N],yi[N],zi[N];

int front[N],nxt[M<<],to[M<<],cap[M<<],tot=;

int lev[N],cur[N];

int src,decc;

queue<int>q;

bool uses[N],uset[N];

void read(int &x)

{

    x=; char c=getchar();

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

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

}

LL turn(int i,int j)

{

    return 1LL*(i-)*m+j;

}

void init()

{

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

    int y,x;

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

    {

        read(yi[i]); read(xi[i]); read(zi[i]);

        mp[turn(xi[i],yi[i])]=i;

    }

    decc=k+;

}

void add(int u,int v,int val)

{

    to[++tot]=v; nxt[tot]=front[u]; front[u]=tot; cap[tot]=val;

    to[++tot]=u; nxt[tot]=front[v]; front[v]=tot; cap[tot]=;

//    printf("%d %d %d\n",u,v,val);

}

void Add(int x,int l,int r,int y)

{

    if(y%== || !(y%))

    {

        uses[x]=true;

        add(x,l,inf);

    }

    else

    {

        uset[x]=true;

        add(r,x,inf);

    }

}

void build()

{

    int x,y;

    int tmp,l,r;

    int l1,l2,l3,r1,r2,r3;

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

    {

        x=xi[i]; y=yi[i];

        if(y==m) continue;

        if(((x&) && y%==) || (!(x&) && y%==))

        {

            tmp=mp[turn(x,y+)];

            if(!tmp) continue;

        }

        else continue;

        if(x>) l1=mp[turn(x-,y)]; else l1=;

        if(x<n) l2=mp[turn(x+,y)];    else l2=;

        if(y>) l3=mp[turn(x,y-)]; else l3=;

        if(!(l1||l2||l3)) continue;

        if(x>) r1=mp[turn(x-,y+)]; else r1=;

        if(x<n) r2=mp[turn(x+,y+)]; else r2=;

        if(y<n-) r3=mp[turn(x,y+)]; else r3=;

        if(!(r1||r2||r3)) continue;

        l=i; r=tmp;

        if(y%==) swap(l,r);

        add(l,r,min(zi[l],zi[r]));

        if(l1) Add(l1,l,r,yi[l1]);

        if(l2) Add(l2,l,r,yi[l2]);

        if(l3) Add(l3,l,r,yi[l3]);

        if(r1) Add(r1,l,r,yi[r1]);

        if(r2) Add(r2,l,r,yi[r2]);

        if(r3) Add(r3,l,r,yi[r3]);

    }

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

        if(uses[i]) add(src,i,zi[i]);

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

        if(uset[i]) add(i,decc,zi[i]);

}

bool bfs()

{

    while(!q.empty()) q.pop();

    for(int i=src;i<=decc;++i) lev[i]=-,cur[i]=front[i];

    lev[src]=;

    q.push(src);

    int now,t;

    while(!q.empty())

    {

        now=q.front();

        q.pop();

        for(int i=front[now];i;i=nxt[i])

        {

            t=to[i];

            if(lev[t]==- && cap[i])

            {

                lev[t]=lev[now]+;

                if(t==decc) return true;

                q.push(t);

            }

        }

    }

    return false;

}

int dinic(int now,int flow)

{

    if(now==decc) return flow;

    int rest=,delta,t;

    for(int &i=cur[now];i;i=nxt[i])

    {

        t=to[i];

        if(lev[t]>lev[now] && cap[i])

        {

            delta=dinic(t,min(flow-rest,cap[i]));

            if(delta)

            {

                cap[i]-=delta;

                cap[i^]+=delta;

                rest+=delta;

                if(rest==flow) break;

            }

        }

    }

    if(rest!=flow) lev[now]=-;

    return rest;

}

void solve()

{

    int ans=;

    while(bfs()) ans+=dinic(src,inf);

    printf("%d",ans);

}

int main()

{

    freopen("data.in","r",stdin);

    freopen("my.out","w",stdout);

    init();

    build();

    solve();

}