#define _USE_MATH_DEFINES
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>

using namespace std;

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

typedef long long int64;
typedef pair<int, int> ii;
const int MOD = 1e9 + 7;
const int64 INF64 = 1LL << 60;

struct Node {
  int x, y;
  int v;
};

const int N = 2e5 + 10;
Node e[N];
vector<ii> a[N];
bool visit[N];
int64 v[N];
int R, C;

void DFS(int k, int64 val, int x, int64 minv[]) {
  visit[x] = true;
  v[x] = val;
  minv[k] = min(minv[k], v[x]);
  for (auto& it : a[x]) {
    int y = it.first, z = it.second;
    if (visit[y]) continue;
    DFS(1 - k, z - val, y, minv);
  }
}

int main() {
  int n;
  scanf("%d%d%d", &R, &C, &n);
  for (int i = 0; i < n; ++i) {
    int x, y, z;
    scanf("%d%d%d", &x, &y, &z);
    --x; --y;
    a[x].push_back({R + y, z});
    a[R + y].push_back({x, z});
    e[i] = {x, y, z};
  }
  for (int i = 0; i < R + C; ++i) {
    if (visit[i]) continue;
    int64 minv[2] = {INF64, INF64};
    DFS(i < R ? 0 : 1, 0, i, minv);
    if (minv[0] + minv[1] < 0) {
      puts("No");
      return 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    int x = e[i].x, y = e[i].y, z = e[i].v;
    if (v[x] + v[R + y] != z) {
      puts("No");
      return 0;
    }
  }
  puts("Yes");
  return 0;
}
