#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math") #include using namespace std; typedef long long ll; #define pb(...) emplace_back(__VA_ARGS__) #define mp(a, b) make_pair(a, b) #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define lscan(x) scanf("%I64d", &x) #define lprint(x) printf("%I64d", x) #define rep(i, n) for (ll i = 0; i < (n); i++) #define rep2(i, n) for (ll i = (ll)n - 1; i >= 0; i--) #define REP(i, l, r) for (ll i = l; i < (r); i++) #define REP2(i, l, r) for (ll i = (ll)r - 1; i >= (l); i--) #define siz(x) (ll) x.size() template using rque = priority_queue, greater>; template bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; } template bool chmax(T &a, const T &b) { if (b > a) { a = b; return 1; } return 0; } ll gcd(ll a, ll b) { if (a == 0) return b; if (b == 0) return a; ll cnt = a % b; while (cnt != 0) { a = b; b = cnt; cnt = a % b; } return b; } long long extGCD(long long a, long long b, long long &x, long long &y) { if (b == 0) { x = 1; y = 0; return a; } long long d = extGCD(b, a % b, y, x); y -= a / b * x; return d; } struct UnionFind { vector data; int num; UnionFind(int sz) { data.assign(sz, -1); num = sz; } bool unite(int x, int y) { x = find(x), y = find(y); if (x == y) return (false); if (data[x] > data[y]) swap(x, y); data[x] += data[y]; data[y] = x; num--; return (true); } int find(int k) { if (data[k] < 0) return (k); return (data[k] = find(data[k])); } ll size(int k) { return (-data[find(k)]); } bool same(int x, int y) { return find(x) == find(y); } }; template struct ModInt { int x; ModInt() : x(0) { } ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) { } ModInt &operator+=(const ModInt &p) { if ((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int)(1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt &operator++() { return *this += ModInt(1); } ModInt operator++(int) { ModInt tmp = *this; ++*this; return tmp; } ModInt &operator--() { return *this -= ModInt(1); } ModInt operator--(int) { ModInt tmp = *this; --*this; return tmp; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(int64_t n) const { ModInt ret(1), mul(x); while (n > 0) { if (n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt(t); return (is); } static int get_mod() { return mod; } }; ll mpow2(ll x, ll n, ll mod) { ll ans = 1; while (n != 0) { if (n & 1) ans = ans * x % mod; x = x * x % mod; n = n >> 1; } return ans; } ll modinv2(ll a, ll mod) { ll b = mod, u = 1, v = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= mod; if (u < 0) u += mod; return u; } // constexpr int mod = 1000000007; constexpr int mod = 998244353; // constexpr int mod = 31607; using mint = ModInt; mint mpow(mint x, ll n) { mint ans = 1; while (n != 0) { if (n & 1) ans *= x; x *= x; n = n >> 1; } return ans; } // ----- library ------- // ----- library ------- int main() { ios::sync_with_stdio(false); std::cin.tie(nullptr); cout << fixed << setprecision(15); int n, k, m; cin >> n >> k >> m; vector l(m), r(m); rep(i, m) cin >> l[i] >> r[i], l[i]--, r[i]--; vector mi(k, 1e9); rep(i, m) chmin(mi[l[i]], r[i]); vector> v; int tmp = 1e8; rep2(i, k) if (chmin(tmp, mi[i])) v.pb(i, mi[i]); reverse(all(v)); map, mint> dp; dp[{0, -1}] = 1; int sz = v.size(); v.pb(1e9, 1e9); rep(i, sz) { map, mint> ndp; auto [nl, nr] = v[i]; for (auto [cond, val] : dp) { auto [ncnt, keep] = cond; int necnt, nekeep; necnt = ncnt, nekeep = keep; if (nekeep < v[i + 1].first) nekeep = -1; ndp[{necnt, nekeep}] += val; necnt = ncnt + nr - max(nl - 1, keep), nekeep = nr; if (nekeep < v[i + 1].first) nekeep = -1; ndp[{necnt, nekeep}] -= val; } dp = ndp; } mint ans = 0; for (auto [cond, val] : dp) { ans += mpow(k - cond.first, n) * val; } cout << ans << endl; }