#include #define FOR(i, a, n) for(ll i = (ll)a; i < (ll)n; i++) #define FORR(i, n) for(ll i = (ll)n - 1LL; i >= 0LL; i--) #define rep(i, n) FOR(i, 0, n) #define ALL(x) begin(x), end(x) using namespace std; using ll = long long; constexpr ll Mod = 998244353; constexpr ll mod = 1e9 + 7; constexpr ll inf = 1LL << 60; const double PI = acos(-1); template inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } /*-------------------------------------------*/ template class ModInt { int x; public: constexpr ModInt() : x(0) {} constexpr ModInt(int64_t y) : x(y >= 0 ? y % M : (M - (-y) % M) % M) {} constexpr ModInt &operator+=(const ModInt p) { if((x += p.x) >= M) x -= M; return *this; } constexpr ModInt &operator-=(const ModInt p) { if((x += M - p.x) >= M) x -= M; return *this; } constexpr ModInt &operator*=(const ModInt p) { x = (int)(1LL * x * p.x % M); return *this; } constexpr ModInt &operator/=(const ModInt p) { *this *= p.inverse(); return *this; } constexpr ModInt operator-() const { return ModInt(-x); } constexpr ModInt operator+(const ModInt p) const { return ModInt(*this) += p; } constexpr ModInt operator-(const ModInt p) const { return ModInt(*this) -= p; } constexpr ModInt operator*(const ModInt p) const { return ModInt(*this) *= p; } constexpr ModInt operator/(const ModInt p) const { return ModInt(*this) /= p; } constexpr bool operator==(const ModInt p) const { return x == p.x; } constexpr bool operator!=(const ModInt p) const { return x != p.x; } constexpr ModInt inverse() const { int a = x, b = M, u = 1, v = 0, t = 0; while(b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } constexpr ModInt pow(int64_t k) const { ModInt ret(1), mul(x); while(k > 0) { if(k & 1) ret *= mul; mul *= mul; k >>= 1; } return ret; } constexpr friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } constexpr friend istream &operator>>(istream &is, ModInt &a) { int64_t t = 0; is >> t; a = ModInt(t); return (is); } }; using mint = ModInt; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); ll n, l; cin >> n >> l; n = (n + l - 1) / l; cout << ModInt(2).pow(n) - 1 << endl; return 0; }