#include using namespace std; const int64_t MOD = 1e9+7; void add(int64_t& a, int64_t b){ a = (a+b) % MOD; } void mul(int64_t& a, int64_t b){ a = a*b % MOD; } int64_t power_mod(int64_t num, int64_t power){ int64_t prod = 1; num %= MOD; while(power > 0){ if(power&1) prod = prod * num % MOD; num = num * num % MOD; power >>= 1; } return prod; } int64_t extgcd(int64_t a, int64_t b, int64_t& x, int64_t& y){ int64_t d = a; if(b != 0){ d = extgcd(b, a%b, y, x); y -= (a/b) * x; }else{ x = 1; y = 0; } return d; } int64_t inv_mod(int64_t a){ int64_t x, y; extgcd(a, MOD, x, y); return (MOD + x%MOD) % MOD; } int main(){ int64_t P, Q; cin >> P >> Q; const int N = 5e6; vector A(N); A[1] = 1; for(int i=2; i> q; q -= 2; if(q == 0){ cout << 0 << endl; continue; } int64_t ans = (q+1) * A[2*q] % MOD * inv_mod(A[q]) % MOD; add(ans, MOD - 2*A[q+1] % MOD); mul(ans, iv); cout << ans << endl; } return 0; }