#include #define whlie while #define pb push_back #define eb emplace_back #define fi first #define se second #define rep(i,N) for(int i = 0; i < (N); i++) #define repr(i,N) for(int i = (N) - 1; i >= 0; i--) #define rep1(i,N) for(int i = 1; i <= (N) ; i++) #define repr1(i,N) for(int i = (N) ; i > 0 ; i--) #define each(x,v) for(auto& x : v) #define all(v) (v).begin(),(v).end() #define sz(v) ((int)(v).size()) #define vrep(v,it) for(auto it = v.begin(); it != v.end(); it++) #define vrepr(v,it) for(auto it = v.rbegin(); it != v.rend(); it++) #define ini(...) int __VA_ARGS__; in(__VA_ARGS__) #define inl(...) ll __VA_ARGS__; in(__VA_ARGS__) #define ins(...) string __VA_ARGS__; in(__VA_ARGS__) using namespace std; void solve(); using ll = long long; using vl = vector; using vi = vector; using vvi = vector< vector >; constexpr int inf = 1001001001; constexpr ll infLL = (1LL << 61) - 1; struct IoSetupNya {IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(7);} } iosetupnya; template inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; } template inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; } template ostream& operator <<(ostream& os, const pair &p) { os << p.first << " " << p.second; return os; } template istream& operator >>(istream& is, pair &p) { is >> p.first >> p.second; return is; } template ostream& operator <<(ostream& os, const vector &v) { int s = (int)v.size(); rep(i,s) os << (i ? " " : "") << v[i]; return os; } template istream& operator >>(istream& is, vector &v) { for(auto &x : v) is >> x; return is; } void in(){} template void in(T &t,U &...u){ cin >> t; in(u...);} void out(){cout << "\n";} template void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);} templatevoid die(T x){out(x); exit(0);} #ifdef NyaanDebug #include "NyaanDebug.h" #define trc(...) do { cerr << #__VA_ARGS__ << " = "; dbg_out(__VA_ARGS__);} while(0) #define trca(v,...) do { cerr << #v << " = "; array_out(v , __VA_ARGS__ );} while(0) #else #define trc(...) #define trca(...) int main(){solve();} #endif using P = pair; using vp = vector

; constexpr int MOD = /**/ 1000000007; //*/ 998244353; ///////////////// vector fac,finv,inv; void COMinit(int MAX) { MAX++; fac.resize(MAX , 0); finv.resize(MAX , 0); inv.resize(MAX , 0); fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1; for (int i = 2; i < MAX; i++){ fac[i] = fac[i - 1] * i % MOD; inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD; finv[i] = finv[i - 1] * inv[i] % MOD; } } // nCk combination inline long long COM(int n,int k){ if(n < k || k < 0 || n < 0) return 0; else return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD; } // nPk permutation inline long long PER(int n,int k){ if (n < k || k < 0 || n < 0) return 0; else return (fac[n] * finv[n - k]) % MOD; } // nHk homogeneous polynomial inline long long HGP(int n,int k){ if(n == 0 && k == 0) return 1; //問題依存? else if(n < 1 || k < 0) return 0; else return fac[n + k - 1] * (finv[k] * finv[n - 1] % MOD) % MOD; } void solve(){ COMinit(100100); ini(N,K); if(N % 2== 0){ if(K % 2) out(0); else out(COM(N/2 , K/2)); } else { out(COM(N / 2 , K / 2)); } }