#define _USE_MATH_DEFINES #include using namespace std; #define FOR(i,m,n) for(int i=(m);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() using ll = long long; constexpr int INF = 0x3f3f3f3f; constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL; constexpr double EPS = 1e-8; constexpr int MOD = 998244353; // constexpr int MOD = 1000000007; constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1}; constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}; constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1}; template inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; } template inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; } struct IOSetup { IOSetup() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << fixed << setprecision(20); } } iosetup; template struct MInt { unsigned int v; MInt() : v(0) {} MInt(const long long x) : v(x >= 0 ? x % M : x % M + M) {} static constexpr int get_mod() { return M; } static void set_mod(const int divisor) { assert(divisor == M); } static void init(const int x = 10000000) { inv(x, true); fact(x); fact_inv(x); } static MInt inv(const int n, const bool init = false) { // assert(0 <= n && n < M && std::__gcd(n, M) == 1); static std::vector inverse{0, 1}; const int prev = inverse.size(); if (n < prev) { return inverse[n]; } else if (init) { // "n!" and "M" must be disjoint. inverse.resize(n + 1); for (int i = prev; i <= n; ++i) { inverse[i] = -inverse[M % i] * (M / i); } return inverse[n]; } int u = 1, v = 0; for (unsigned int a = n, b = M; b;) { const unsigned int q = a / b; std::swap(a -= q * b, b); std::swap(u -= q * v, v); } return u; } static MInt fact(const int n) { static std::vector factorial{1}; const int prev = factorial.size(); if (n >= prev) { factorial.resize(n + 1); for (int i = prev; i <= n; ++i) { factorial[i] = factorial[i - 1] * i; } } return factorial[n]; } static MInt fact_inv(const int n) { static std::vector f_inv{1}; const int prev = f_inv.size(); if (n >= prev) { f_inv.resize(n + 1); f_inv[n] = inv(fact(n).v); for (int i = n; i > prev; --i) { f_inv[i - 1] = f_inv[i] * i; } } return f_inv[n]; } static MInt nCk(const int n, const int k) { if (n < 0 || n < k || k < 0) return 0; return fact(n) * (n - k < k ? fact_inv(k) * fact_inv(n - k) : fact_inv(n - k) * fact_inv(k)); } static MInt nPk(const int n, const int k) { return n < 0 || n < k || k < 0 ? 0 : fact(n) * fact_inv(n - k); } static MInt nHk(const int n, const int k) { return n < 0 || k < 0 ? 0 : (k == 0 ? 1 : nCk(n + k - 1, k)); } static MInt large_nCk(long long n, const int k) { if (n < 0 || n < k || k < 0) return 0; inv(k, true); MInt res = 1; for (int i = 1; i <= k; ++i) { res *= inv(i) * n--; } return res; } MInt pow(long long exponent) const { MInt res = 1, tmp = *this; for (; exponent > 0; exponent >>= 1) { if (exponent & 1) res *= tmp; tmp *= tmp; } return res; } MInt& operator+=(const MInt& x) { if ((v += x.v) >= M) v -= M; return *this; } MInt& operator-=(const MInt& x) { if ((v += M - x.v) >= M) v -= M; return *this; } MInt& operator*=(const MInt& x) { v = static_cast(v) * x.v % M; return *this; } MInt& operator/=(const MInt& x) { return *this *= inv(x.v); } bool operator==(const MInt& x) const { return v == x.v; } bool operator!=(const MInt& x) const { return v != x.v; } bool operator<(const MInt& x) const { return v < x.v; } bool operator<=(const MInt& x) const { return v <= x.v; } bool operator>(const MInt& x) const { return v > x.v; } bool operator>=(const MInt& x) const { return v >= x.v; } MInt& operator++() { if (++v == M) v = 0; return *this; } MInt operator++(int) { const MInt res = *this; ++*this; return res; } MInt& operator--() { v = (v == 0 ? M - 1 : v - 1); return *this; } MInt operator--(int) { const MInt res = *this; --*this; return res; } MInt operator+() const { return *this; } MInt operator-() const { return MInt(v ? M - v : 0); } MInt operator+(const MInt& x) const { return MInt(*this) += x; } MInt operator-(const MInt& x) const { return MInt(*this) -= x; } MInt operator*(const MInt& x) const { return MInt(*this) *= x; } MInt operator/(const MInt& x) const { return MInt(*this) /= x; } friend std::ostream& operator<<(std::ostream& os, const MInt& x) { return os << x.v; } friend std::istream& operator>>(std::istream& is, MInt& x) { long long v; is >> v; x = MInt(v); return is; } }; using ModInt = MInt; struct UnionFind { explicit UnionFind(const int n) : data(n, -1) {} int root(const int ver) { return data[ver] < 0 ? ver : data[ver] = root(data[ver]); } bool unite(int u, int v) { u = root(u); v = root(v); if (u == v) return false; if (data[u] > data[v]) std::swap(u, v); data[u] += data[v]; data[v] = u; return true; } bool is_same(const int u, const int v) { return root(u) == root(v); } int size(const int ver) { return -data[root(ver)]; } private: std::vector data; }; std::vector prime_sieve(const int n, const bool get_only_prime) { std::vector smallest_prime_factor(n + 1), prime; std::iota(smallest_prime_factor.begin(), smallest_prime_factor.end(), 0); for (int i = 2; i <= n; ++i) { if (smallest_prime_factor[i] == i) prime.emplace_back(i); for (const int p : prime) { if (i * p > n || p > smallest_prime_factor[i]) break; smallest_prime_factor[i * p] = p; } } return get_only_prime ? prime : smallest_prime_factor; } struct OsaK { const std::vector smallest_prime_factor; explicit OsaK(const int n) : smallest_prime_factor(prime_sieve(n, false)) {} std::vector> query(int n) const { std::vector> res; while (n > 1) { const int prime = smallest_prime_factor[n]; int exponent = 0; for (; smallest_prime_factor[n] == prime; n /= prime) { ++exponent; } res.emplace_back(prime, exponent); } return res; } }; int main() { int n, p, q; cin >> n >> p >> q; if (n == 1) { cout << 1 << '\n'; return 0; } if (p + q <= n) { cout << (p == 1 ? 1 : 2) * (q == 1 ? 1 : 2) << '\n'; return 0; } if (p == 1 || q == 1) { cout << 2 << '\n'; return 0; } if (p == n && q == n) { cout << 2 << '\n'; return 0; } UnionFind union_find(n); REP(i, p) union_find.unite(i, p - 1 - i); REP(i, q) union_find.unite(n - q + i, n - 1 - i); map lcm; OsaK osa_k(n); REP(i, n) { if (union_find.root(i) == i) { for (const auto& [p, ex] : osa_k.query(union_find.size(i))) { chmax(lcm[p], ex); } } } ModInt ans = 1; for (const auto& [p, ex] : lcm) { ans *= ModInt(p).pow(ex); } cout << ans * 2 << '\n'; return 0; // for (int n = 1; n <= N; ++n) { // cout << n << ":\n"; // vector init(n); // iota(ALL(init), 0); // for (int p = 1; p <= n; ++p) { // for (int q = n - p + 1; q <= n; ++q) { // // for (int q = max(n - p + 1, p); q <= n; ++q) { // set> dp{init}; // queue> que({init}); // while (!que.empty()) { // vector a = que.front(); que.pop(); // reverse(a.begin(), next(a.begin(), p)); // if (dp.emplace(a).second) que.emplace(a); // reverse(a.begin(), next(a.begin(), p)); // reverse(prev(a.end(), q), a.end()); // if (dp.emplace(a).second) que.emplace(a); // } // cout << dp.size() << " \n"[q == n]; // } // } // cout << '\n'; // } }