#include <bits/stdc++.h>

using i64 = long long;
template<class T>
constexpr T power(T a, i64 b) {
    T res = 1;
    for (; b; b /= 2, a *= a) {
        if (b % 2) {
            res *= a;
        }
    }
    return res;
}

constexpr i64 mul(i64 a, i64 b, i64 p) {
    i64 res = a * b - i64(1.L * a * b / p) * p;
    res %= p;
    if (res < 0) {
        res += p;
    }
    return res;
}
template<i64 P>
struct MLong {
    i64 x;
    constexpr MLong() : x{} {}
    constexpr MLong(i64 x) : x{norm(x % getMod())} {}
    
    static i64 Mod;
    constexpr static i64 getMod() {
        if (P > 0) {
            return P;
        } else {
            return Mod;
        }
    }
    constexpr static void setMod(i64 Mod_) {
        Mod = Mod_;
    }
    constexpr i64 norm(i64 x) const {
        if (x < 0) {
            x += getMod();
        }
        if (x >= getMod()) {
            x -= getMod();
        }
        return x;
    }
    constexpr i64 val() const {
        return x;
    }
    explicit constexpr operator i64() const {
        return x;
    }
    constexpr MLong operator-() const {
        MLong res;
        res.x = norm(getMod() - x);
        return res;
    }
    constexpr MLong inv() const {
        assert(x != 0);
        return power(*this, getMod() - 2);
    }
    constexpr MLong &operator*=(MLong rhs) & {
        x = mul(x, rhs.x, getMod());
        return *this;
    }
    constexpr MLong &operator+=(MLong rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MLong &operator-=(MLong rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MLong &operator/=(MLong rhs) & {
        return *this *= rhs.inv();
    }
    friend constexpr MLong operator*(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MLong operator+(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MLong operator-(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MLong operator/(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MLong &a) {
        i64 v;
        is >> v;
        a = MLong(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MLong &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MLong lhs, MLong rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MLong lhs, MLong rhs) {
        return lhs.val() != rhs.val();
    }
};

template<>
i64 MLong<0LL>::Mod = i64(1E18) + 9;

template<int P>
struct MInt {
    int x;
    constexpr MInt() : x{} {}
    constexpr MInt(i64 x) : x{norm(x % getMod())} {}
    
    static int Mod;
    constexpr static int getMod() {
        if (P > 0) {
            return P;
        } else {
            return Mod;
        }
    }
    constexpr static void setMod(int Mod_) {
        Mod = Mod_;
    }
    constexpr int norm(int x) const {
        if (x < 0) {
            x += getMod();
        }
        if (x >= getMod()) {
            x -= getMod();
        }
        return x;
    }
    constexpr int val() const {
        return x;
    }
    explicit constexpr operator int() const {
        return x;
    }
    constexpr MInt operator-() const {
        MInt res;
        res.x = norm(getMod() - x);
        return res;
    }
    constexpr MInt inv() const {
        assert(x != 0);
        return power(*this, getMod() - 2);
    }
    constexpr MInt &operator*=(MInt rhs) & {
        x = 1LL * x * rhs.x % getMod();
        return *this;
    }
    constexpr MInt &operator+=(MInt rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MInt &operator-=(MInt rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MInt &operator/=(MInt rhs) & {
        return *this *= rhs.inv();
    }
    friend constexpr MInt operator*(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MInt operator+(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MInt operator-(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MInt operator/(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MInt &a) {
        i64 v;
        is >> v;
        a = MInt(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MInt &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MInt lhs, MInt rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MInt lhs, MInt rhs) {
        return lhs.val() != rhs.val();
    }
};

template<>
int MInt<0>::Mod = 998244353;

template<int V, int P>
constexpr MInt<P> CInv = MInt<P>(V).inv();

constexpr int P = 998244353;
using Z = MInt<P>;

struct Comb {
    int n;
    std::vector<Z> _fac;
    std::vector<Z> _invfac;
    std::vector<Z> _inv;
    
    Comb() : n{0}, _fac{1}, _invfac{1}, _inv{0} {}
    Comb(int n) : Comb() {
        init(n);
    }
    
    void init(int m) {
        m = std::min(m, Z::getMod() - 1);
        if (m <= n) return;
        _fac.resize(m + 1);
        _invfac.resize(m + 1);
        _inv.resize(m + 1);
        
        for (int i = n + 1; i <= m; i++) {
            _fac[i] = _fac[i - 1] * i;
        }
        _invfac[m] = _fac[m].inv();
        for (int i = m; i > n; i--) {
            _invfac[i - 1] = _invfac[i] * i;
            _inv[i] = _invfac[i] * _fac[i - 1];
        }
        n = m;
    }
    
    Z fac(int m) {
        if (m > n) init(2 * m);
        return _fac[m];
    }
    Z invfac(int m) {
        if (m > n) init(2 * m);
        return _invfac[m];
    }
    Z inv(int m) {
        if (m > n) init(2 * m);
        return _inv[m];
    }
    Z binom(int n, int m) {
        if (n < m || m < 0) return 0;
        return fac(n) * invfac(m) * invfac(n - m);
    }
} comb;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n, m, k;
    std::cin >> n >> m >> k;
    
    std::vector<int> x(k), y(k);
    for (int i = 0; i < k; i++) {
        std::cin >> x[i] >> y[i];
        if (n > m) {
            std::swap(x[i], y[i]);
        }
    }
    if (n > m) {
        std::swap(n, m);
    }
    
    std::vector<int> px(k), py(k);
    std::iota(px.begin(), px.end(), 0);
    std::sort(px.begin(), px.end(),
        [&](int i, int j) {
            return x[i] < x[j];
        });
    std::iota(py.begin(), py.end(), 0);
    std::sort(py.begin(), py.end(),
        [&](int i, int j) {
            return y[i] < y[j];
        });
    std::vector<int> qx(k), qy(k);
    for (int i = 0; i < k; i++) {
        qx[px[i]] = i;
        qy[py[i]] = i;
    }
    
    Z ans = Z(n) * (1 + n) * (2 + n) * (Z(-4) + n + Z(3) * n * n - Z(5) * m * (1 + n)) / -60;
    
    auto get = [&](int x1, int y1, int x2, int y2) {
        Z res = 0;
        int bx = std::min(x1, n - x2);
        int dx = x2 - x1 + 1;
        int by = std::min(y1, m - y2);
        int dy = y2 - y1 + 1;
        int L = std::max(dx + 1, dy + 1);
        int R = std::min(n, m);
        if (L > R) {
            return res;
        }
        std::vector<int> s{L, R};
        s.push_back(bx + dx);
        s.push_back(n + 1 - bx);
        s.push_back((n + 1 + dx) / 2);
        s.push_back((n + 1 + dx) / 2 + 1);
        s.push_back(by + dy);
        s.push_back(m + 1 - by);
        s.push_back((m + 1 + dy) / 2);
        s.push_back((m + 1 + dy) / 2 + 1);
        std::sort(s.begin(), s.end());
        auto get = [&](int d) {
            return Z(d) * d * std::max(0, std::min({bx, d - dx, n + 1 - d}))
                * std::max(0, std::min({by, d - dy, m + 1 - d}));
        };
        for (int i = 0; i < s.size() - 1; i++) {
            int l = s[i], r = s[i + 1];
            if (l == r || r <= L || l >= R) {
                continue;
            }
            // if (r - l < 5) {
            //     for (int x = l; x < r; x++) {
            //         res += get(x);
            //     }
            //     continue;
            // }
            std::array<Z, 6> f;
            f[0] = 0;
            for (int j = 0; j < 5; j++) {
                f[j + 1] = f[j] + get(l + j);
            }
            for (int x = 0; x <= 5; x++) {
                Z v = 1;
                for (int y = 0; y <= 5; y++) {
                    if (y != x) {
                        v = v * (r - l - y) / (x - y);
                    }
                }
                res += v * f[x];
            }
        }
        res += get(R);
        return res;
    };
    
    for (int i = 0; i < k; i++) {
        ans -= get(x[i], y[i], x[i], y[i]);
    }
    for (int i = 0; i < k; i++) {
        std::vector<int> l(k, -1), r(k, -1);
        int lst = -1;
        for (int j = 0; j < k; j++) {
            if (qx[py[j]] >= i) {
                if (lst != -1) {
                    l[py[j]] = lst;
                    r[lst] = py[j];
                }
                lst = py[j];
            }
        }
        for (int j = k - 1; j > i; j--) {
            int a = px[i], b = px[j];
            int x1 = x[a], x2 = x[b];
            if (qy[a] > qy[b]) {
                std::swap(a, b);
            }
            if (r[a] == b) {
                ans += get(x1, y[a], x2, y[b]);
                if (l[a] != -1) {
                    ans -= get(x1, y[l[a]], x2, y[b]);
                }
                if (r[b] != -1) {
                    ans -= get(x1, y[a], x2, y[r[b]]);
                }
                if (l[a] != -1 && r[b] != -1) {
                    ans += get(x1, y[l[a]], x2, y[r[b]]);
                }
            }
            a = px[j];
            if (l[a] != -1) {
                r[l[a]] = r[a];
            }
            if (r[a] != -1) {
                l[r[a]] = l[a];
            }
        }
    }
    
    std::cout << ans << "\n";
    
    return 0;
}