#ifdef mmlang_source_25_lines

R, C, K = inputInt(), inputInt(), inputInt()
rcv[:K] = inputInt() - 1, inputInt() - 1, inputInt()
rcv.sort()
V[:R][:C] = 0
for r, c, v in rcv:
    V[r][c] = v
D[:R][:C][:4] = 0LL
@memo
def solve(r, c, i)->int64:
    ret = 0LL
    if 1 <= i:
        ret >?= V[r][c]
    if 1 <= r:
        if i == 1:
            ret >?= solve(r - 1, c, : 4) + V[r][c]
        elif i == 0:
            ret >?= solve(r - 1, c, : 4)
    if 1 <= c:
        if 1 <= i:
            ret >?= solve(r, c - 1, i - 1) + V[r][c]
        ret >?= solve(r, c - 1, i)
    return ret
ans = 0
ans >?= solve(R - 1, C - 1, : 4)
print(ans)

#endif

//#define NDEBUG

#include <cassert>
#include <vector>
#include <deque>
#include <string>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <cstdlib>
#include <cstdio>
#include <cstring>

using namespace std;

typedef long long int64;typedef __int128 int128;const char*inputCLineOrWord(int mode){static char buf[2097152];static int bufLen=sizeof(buf);static int bufPos=sizeof(buf);static bool canReadFlag=true;static bool crFlag=false;static bool enterFlag=false;if(canReadFlag&&(enterFlag?bufLen<=bufPos:(int)sizeof(buf)<=bufPos+bufPos)){if(0<bufLen-bufPos){memmove(buf,buf+bufPos,bufLen-bufPos);bufLen-=bufPos;}else{bufLen=0;}char*result=fgets(buf+bufLen,sizeof(buf)-bufLen,stdin);canReadFlag=(result!=NULL);if(result!=NULL){int n=strlen(result);enterFlag=(n!=(int)sizeof(buf)-1-bufLen||(1<=bufLen+n&&buf[bufLen+n-1]=='\n'));bufLen+=n;}bufPos=0;}if(mode==0){int pos=bufPos;while(true){char c=buf[pos];if(c==32){buf[pos++]='\0';break;}else if(c==10){if(crFlag){crFlag=false;if(bufPos==pos){pos=++bufPos;continue;}}buf[pos++]='\0';break;}else if(c==13){crFlag=true;buf[pos++]='\0';break;}else if(c==0){break;}++pos;}const char*ret=buf+bufPos;bufPos=pos;while(true){char c=buf[bufPos];if(c==32||c==10||c==13){++bufPos;}else{break;}}return ret;}else if(mode==1){int pos=bufPos;while(true){char c=buf[pos];if(c==10){if(crFlag){crFlag=false;if(bufPos==pos){pos=++bufPos;continue;}}buf[pos++]='\0';break;}else if(c==13){crFlag=true;buf[pos++]='\0';break;}else if(c==0){break;}++pos;}const char*ret=buf+bufPos;bufPos=pos;if(crFlag){while(true){char c=buf[bufPos];if(c==13){++bufPos;crFlag=false;break;}else{break;}}}return ret;}else if(mode==2){return bufLen<=bufPos?NULL:buf+bufPos;}assert(false);return NULL;}const char*inputCWord(){return inputCLineOrWord(0);}int inputInt(){return atoi(inputCWord());}void print_unit(bool val){printf("%s",val?"true":"false");}void print_unit(char val){printf("%c",val);}void print_unit(int val){printf("%d",val);}void print_unit(unsigned int val){printf("%u",val);}void print_unit(size_t val){printf("%zd",val);}void print_unit(const void*val){printf("%p",val);}void print_unit(long long val){printf("%lld",val);}void print_unit(__int128 val){char buf[128];int idx=128;buf[--idx]='\0';bool sign=false;if(val<0){sign=true;val=-val;}if(val==0){buf[--idx]='0';}else while(val){buf[--idx]='0'+(val % 10);val /=10;}if(sign){buf[--idx]='-';}printf("%s",buf+idx);}void print_unit(double val){printf("%g",val);}void print_unit(const char*val){printf("%s",val);}void print_unit(const std::string&val){printf("%s",val.c_str());}template<class T>void print_unit(const std::vector<T>&val){printf("vec(%d) {",(int)val.size());for(int i=0;i<(int)val.size();++i){fputc(' ',stdout);print_unit(val[i]);}printf(" }");}
#define _print0()
#define _print1(e)print_unit(e)
#define _print2(e1,e2)_print1(e1),fputc(' ',stdout),_print1(e2)
#define _print3(e1,e2,e3)_print2(e1,e2),fputc(' ',stdout),_print1(e3)
#define _print4(e1,e2,e3,e4)_print2(e1,e2),fputc(' ',stdout),_print2(e3,e4)
#define _print5(e1,e2,e3,e4,e5)_print3(e1,e2,e3),fputc(' ',stdout),_print2(e4,e5)
#define _print6(e1,e2,e3,e4,e5,e6)_print3(e1,e2,e3),fputc(' ',stdout),_print3(e4,e5,e6)
#define _print7(e1,e2,e3,e4,e5,e6,e7)_print4(e1,e2,e3,e4),fputc(' ',stdout),_print3(e5,e6,e7)
#define _print8(e1,e2,e3,e4,e5,e6,e7,e8)_print4(e1,e2,e3,e4),fputc(' ',stdout),_print4(e5,e6,e7,e8)
#define _print9(e1,e2,e3,e4,e5,e6,e7,e8,e9)_print5(e1,e2,e3,e4,e5),fputc(' ',stdout),_print4(e6,e7,e8,e9)
#define _print10(e1,e2,e3,e4,e5,e6,e7,e8,e9,e10)_print5(e1,e2,e3,e4,e5),fputc(' ',stdout),_print5(e6,e7,e8,e9,e10)
#define _GET_PRINT_MACRO_NAME(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,NAME,...)NAME
#define print(...)_GET_PRINT_MACRO_NAME(__VA_ARGS__,_print10,_print9,_print8,_print7,_print6,_print5,_print4,_print3,_print2,_print1,_print0)(__VA_ARGS__),fputc('\n',stdout)
#define print0(...)_GET_PRINT_MACRO_NAME(__VA_ARGS__,_print10,_print9,_print8,_print7,_print6,_print5,_print4,_print3,_print2,_print1,_print0)(__VA_ARGS__)

// generated code (by mmlang) :

int64 solve(int r, int c, int i);

int R;
int C;
int K;
vector<tuple<int, int, int> > rcv;
vector<vector<int> > V;
vector<vector<vector<long long> > > D;
int64 ans;

int64 solve$origin(int r, int c, int i) {
    long long ret;
    ret = 0LL;
    if(1 <= i) {
        ret = max(ret, (long long)(V[r][c]));
    }
    if(1 <= r) {
        if(i == 1) {
            for(int $1=0, $e=4; $1<$e; ++$1) ret = max(ret, (long long)(solve(r - 1, c, $1) + V[r][c]));
        }
        else if(i == 0) {
            for(int $1=0, $e=4; $1<$e; ++$1) ret = max(ret, (long long)(solve(r - 1, c, $1)));
        }
    }
    if(1 <= c) {
        if(1 <= i) {
            ret = max(ret, (long long)(solve(r, c - 1, i - 1) + V[r][c]));
        }
        ret = max(ret, (long long)(solve(r, c - 1, i)));
    }
    return ret;
}
vector<int64> solve$memo;
int64 solve(int r, int c, int i) {
    if(solve$memo.empty()) {
        solve$memo.resize(R*C*4, 0x8000000000000000LL);
    }
    int idx = r*C*4+c*4+i;
    if(solve$memo[idx]!=0x8000000000000000LL) {
        return solve$memo[idx];
    }
    solve$memo[idx] = 0LL;
    auto ret = solve$origin(r, c, i);
    solve$memo[idx] = ret;
    return ret;
}

int main() {
    {
        const auto & $c1 = inputInt();
        const auto & $c2 = inputInt();
        const auto & $c3 = inputInt();
        tie(R, C, K) = tuple<int, int, int>($c1, $c2, $c3);
    }
    {
        rcv.resize(max((int)rcv.size(), (int)K));
        for(int $1=0, $e=(0<=K ? K : (int)rcv.size()+K); $1<$e; ++$1) {
            const auto & $c1 = inputInt() - 1;
            const auto & $c2 = inputInt() - 1;
            const auto & $c3 = inputInt();
            rcv[$1] = tuple<int, int, int>($c1, $c2, $c3);
        }
    }
    sort(rcv.begin(), rcv.end());
    {
        V.resize(max((int)V.size(), (int)R));
        for(int $1=0, $e=(0<=R ? R : (int)V.size()+R); $1<$e; ++$1) {
            V[$1].resize(max((int)V[$1].size(), (int)C));
            for(int $2=0, $e=(0<=C ? C : (int)V[$1].size()+C); $2<$e; ++$2) V[$1][$2] = 0;
        }
    }
    for(const tuple<int, int, int> & $fr : rcv) { const int & r = get<0>($fr); const int & c = get<1>($fr); const int & v = get<2>($fr);
        V[r][c] = v;
    }
    {
        D.resize(max((int)D.size(), (int)R));
        for(int $1=0, $e=(0<=R ? R : (int)D.size()+R); $1<$e; ++$1) {
            D[$1].resize(max((int)D[$1].size(), (int)C));
            for(int $2=0, $e=(0<=C ? C : (int)D[$1].size()+C); $2<$e; ++$2) {
                D[$1][$2].resize(max((int)D[$1][$2].size(), (int)4));
                for(int $3=0, $e=(0<=4 ? 4 : (int)D[$1][$2].size()+4); $3<$e; ++$3) D[$1][$2][$3] = 0LL;
            }
        }
    }
    ans = 0;
    for(int $1=0, $e=4; $1<$e; ++$1) ans = max(ans, solve(R - 1, C - 1, $1));
    print(ans);
    return 0;
}


Measured memory_bytes: 956464