#include <bits/stdc++.h>
#define ALL(v) std::begin(v), std::end(v)
#define ALLR(v) std::rbegin(v), std::rend(v)
using ll = std::int64_t;
using ull = std::uint64_t;
using pll = std::pair<ll, ll>;
using tll = std::tuple<ll, ll, ll>;
template <typename T> using vec = std::vector<T>;
template <typename T> using vvec = vec<vec<T>>;
template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return std::min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return std::max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> const T& clamp(const T &t, const T &low, const T &high) { return std::max(low, std::min(high, t)); }
template <typename T> void chclamp(T &t, const T &low, const T &high) { return t = clamp(t, low, high); }
template <typename T> T make_v(T init) { return init; }
template <typename T, typename... Tail> auto make_v(T init, std::size_t s, Tail... tail) { auto v = std::move(make_v(init, tail...)); return vec<decltype(v)>(s, v); }
template <typename T, std::size_t Head, std::size_t ...Tail> struct multi_dem_array { using type = std::array<typename multi_dem_array<T, Tail...>::type, Head>; };
template <typename T, std::size_t Head> struct multi_dem_array<T, Head> { using type = std::array<T, Head>; };
template <typename T, std::size_t ...Args> using mdarray = typename multi_dem_array<T, Args...>::type;
namespace init__ { struct InitIO { InitIO() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(30); } } init_io; }

const ll inf= 5e15;

bool dfs(ll idx, const vvec<tll> &cons, vec<bool> &used, vec<ll> &vals, std::set<ll> &def) {
    if (used[idx]) return true;
    used[idx] = true;
    bool ret = true;
    for (auto &&e : cons[idx]) {
        ll i1, i2, v1, v2;
        i1 = idx;
        std::tie(i2, v1, v2) = e;
        if (vals[i1] != inf && vals[i2] != inf) {
            ll d1 = vals[i1] - vals[i2];
            ll d2 = v1 - v2;
            if (d1 != d2) return false;
        } else if (vals[i1] != inf) {
            vals[i2] = vals[i1] - v1 + v2;
            def.insert(i2);
        } else if (vals[i2] != inf) {
            vals[i1] = vals[i2] - v2 + v1;
            def.insert(i1);
        } else {
            vals[i1] = v1;
            vals[i2] = v2;
            def.insert(i1);
            def.insert(i2);
        }
        ret &= dfs(i2, cons, used, vals, def);
    }

    return ret;
}

bool check(const vvec<pll> &lines, ll w) {
    vvec<tll> cons(1e5 + 10);
    vec<ll> minv(w, inf);
    for (auto &&line : lines) {
        for (pll p : line) {
            ll c, a;
            std::tie(c, a) = p;
            chmin(minv[c], a);
        }
        if (line.size() < 2) continue;
        for (ll i = (ll)(line.size()) - 2; 0 <= i; i--) {
            ll i1, i2, v1, v2;
            std::tie(i1, v1) = line[i];
            std::tie(i2, v2) = line[i + 1];
            cons[i1].emplace_back(i2, v1, v2);
            cons[i2].emplace_back(i1, v2, v1);
        }
    }

    vec<ll> vals(w, inf);
    vec<bool> used(cons.size(), false);

    for (ll i = 0; i < cons.size(); i++) {
        if (used[i]) continue;
        std::set<ll> def;
        if (!dfs(i, cons, used, vals, def)) return false;
        ll dec = 0;
        for (ll e : def) chmax(dec, vals[e] - minv[e]);
        for (ll e : def) {
            vals[e] -= dec;
            if (vals[e] < 0) return false;
        }
    }

    return true;
}

bool solve() {
    ll r, c, n;
    std::cin >> r >> c >> n;
    vvec<pll> rows(r), cols(c);
    for (ll i = 0; i < n; i++) {
        ll ri, ci, a;
        std::cin >> ri >> ci >> a;
        ri--; ci--;
        rows[ri].emplace_back(ci, a);
        cols[ci].emplace_back(ri, a);
    }

    for (auto &&v : rows) std::sort(ALL(v));
    for (auto &&v : cols) std::sort(ALL(v));

    return check(rows, c) && check(cols, r);
}

int main() {
    std::cout << (solve() ? "Yes" : "No") << '\n';
    return 0;
}


Measured memory_bytes: 25144