#pragma region Macros // #pragma GCC target("avx,avx2,fma") // #pragma GCC optimize("O3,unroll-loops") #include // #include // using namespace atcoder; using namespace std; using namespace __gnu_pbds; // #include // #include // namespace mp = boost::multiprecision; // using Bint = mp::cpp_int; // using Bdouble = mp::number>; #define TO_STRING(var) # var #define pb emplace_back #define int ll #define endl '\n' #define sqrt __builtin_sqrt using ll = long long; using ld = long double; const ld PI = acos(-1); const ld EPS = 1e-10; const int INF = 1 << 30; const ll INFL = 1LL << 61; // const int MOD = 998244353; const int MOD = 1000000007; __attribute__((constructor)) void constructor() { ios::sync_with_stdio(false); cin.tie(nullptr); // ifstream in("input.txt"); // cin.rdbuf(in.rdbuf()); cout << fixed << setprecision(12); } class UnionFind { public: UnionFind() = default; UnionFind(int N) : par(N), sz(N, 1) { iota(par.begin(), par.end(), 0); } int root(int x) { if (par[x] == x) return x; return (par[x] = root(par[x])); } bool unite(int x, int y) { int rx = root(x); int ry = root(y); if (rx == ry) return false; if (sz[rx] < sz[ry]) swap(rx, ry); sz[rx] += sz[ry]; par[ry] = rx; return true; } bool issame(int x, int y) { return (root(x) == root(y)); } int size(int x) { return sz[root(x)]; } vector> groups(int N) { vector> G(N); for (int x = 0; x < N; x++) { G[root(x)].push_back(x); } G.erase( remove_if(G.begin(), G.end(), [&](const vector& V) { return V.empty(); }), G.end()); return G; } private: vector par; vector sz; }; template class Modint{ public: int val = 0; Modint(int x = 0) { while (x < 0) x += mod; val = x % mod; } Modint(const Modint &r) { val = r.val; } Modint operator -() { return Modint(-val); } Modint operator +(const Modint &r) { return Modint(*this) += r; } Modint operator +(const int &q) { Modint r(q); return Modint(*this) += r; } Modint operator -(const Modint &r) { return Modint(*this) -= r; } Modint operator -(const int &q) { Modint r(q); return Modint(*this) -= r; } Modint operator *(const Modint &r) { return Modint(*this) *= r; } Modint operator *(const int &q) { Modint r(q); return Modint(*this) *= r; } Modint operator /(const Modint &r) { return Modint(*this) /= r; } Modint operator /(const int &q) { Modint r(q); return Modint(*this) /= r; } Modint& operator ++() { val = (val + 1) % mod; return *this; } Modint& operator --() { val = (val - 1 + mod) % mod; return *this; } Modint &operator +=(const Modint &r) { val += r.val; if (val >= mod) val -= mod; return *this; } Modint &operator +=(const int &q) { Modint r(q); val += r.val; if (val >= mod) val -= mod; return *this; } Modint &operator -=(const Modint &r) { if (val < r.val) val += mod; val -= r.val; return *this; } Modint &operator -=(const int &q) { Modint r(q); if (val < r.val) val += mod; val -= r.val; return *this; } Modint &operator *=(const Modint &r) { val = val * r.val % mod; return *this; } Modint &operator *=(const int &q) { Modint r(q); val = val * r.val % mod; return *this; } Modint &operator /=(const Modint &r) { int a = r.val, b = mod, u = 1, v = 0; while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);} val = val * u % mod; if (val < 0) val += mod; return *this; } Modint &operator /=(const int &q) { Modint r(q); int a = r.val, b = mod, u = 1, v = 0; while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);} val = val * u % mod; if (val < 0) val += mod; return *this; } bool operator ==(const Modint& r) { return this -> val == r.val; } bool operator <(const Modint& r) { return this -> val < r.val; } bool operator !=(const Modint& r) { return this -> val != r.val; } }; using mint = Modint; // using mint = modint; istream &operator >>(istream &is, mint& x) { int t; is >> t; x = t; return (is); } ostream &operator <<(ostream &os, const mint& x) { return os << x.val; } mint modpow(const mint &x, int n) { if (n == 0) return 1; mint t = modpow(x, n / 2); t = t * t; if (n & 1) t = t * x; return t; } int modpow(__int128_t x, int n, int mod) { __int128_t ret = 1; while (n > 0) { if (n % 2 == 1) ret = ret * x % mod; x = x * x % mod; n /= 2; } return ret; } int POW(int x, int n) { __int128_t ret = 1; if (n < 0) { cout << "error" << endl; return 0; } else if (x == 1 or n == 0) ret = 1; else if (x == -1 && n % 2 == 0) ret = 1; else if (x == -1) ret = -1; else if (n % 2 == 0) ret = POW(x * x, n / 2); else ret = x * POW(x, n - 1); if (ret > 8e18) ret = 0; // llに収まらない範囲は0埋め return ret; } int floor(int x, int y) { return (x > 0 ? x / y : (x - y + 1) / y); } int ceil(int x, int y) { return (x > 0 ? (x + y - 1) / y : x / y); } int per(int x, int y) { if (y == 0) { cout << "error" << endl; return INFL; } if (x >= 0 && y > 0) return x / y; if (x >= 0 && y < 0) return x / y - (x % y < 0); if (x < 0 && y < 0) return x / y + (x % y < 0); if (x < 0 && y > 0) return x / y - (x % y < 0); } int mod(int x, int y) { if (y == 0) { cout << "error" << endl; return INFL; } if (x >= 0 && y > 0) return x % y; if (x >= 0 && y < 0) return x % y; if (x < 0 && y < 0) { __int128_t ret = x % y; ret += (__int128_t)abs(y) * INFL; ret %= abs(y); return ret; } if (x < 0 && y > 0) { __int128_t ret = x % y; ret += (__int128_t)abs(y) * INFL; ret %= abs(y); return ret; } } template bool chmax(T &a, const T& b) { if (a < b) { a = b; return true; } return false; } template bool chmin(T &a, const T& b) { if (a > b) { a = b; return true; } return false; } int countl_zero(int N) { return __builtin_clzll(N); } int countl_one(int N) { int ret = 0; while (N % 2) { N /= 2; ret++; } return ret; } int countr_zero(int N) { return __builtin_ctzll(N); } int countr_one(int N) { int ret = 0, k = 63 - __builtin_clzll(N); while (k != -1 && (N & (1LL << k))) { k--; ret++; } return ret; } int popcount(int N) { return __builtin_popcountll(N); } int unpopcount(int N) { return 64 - __builtin_clzll(N) - __builtin_popcountll(N); } int top_bit(int N) { return 63 - __builtin_clzll(N);} // 2^kの位 int bot_bit(int N) { return __builtin_ctz(N);} // 2^kの位 int MSB(int N) { return 1 << (63 - __builtin_clzll(N)); } // mask int LSB(int N) { return (N & -N); } // mask int bit_width(int N) { return 64 - __builtin_clzll(N); } // 桁数 int ceil_log2(int N) { return 63 - __builtin_clzll(N); } int bit_floor(int N) { return 1 << (63 - __builtin_clzll(N)); } int floor_log2(int N) { return 64 - __builtin_clzll(N-1); } int bit_ceil(int N) { return 1 << (64 - __builtin_clzll(N-1)) - (N==1); } vector fac, finv, Inv; void COMinit(int N) { fac.resize(N + 1); finv.resize(N + 1); Inv.resize(N + 1); fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; Inv[1] = 1; for (int i = 2; i <= N; i++) { fac[i] = fac[i-1] * mint(i); Inv[i] = -Inv[MOD % i] * mint(MOD / i); finv[i] = finv[i - 1] * Inv[i]; } } mint COM(int N, int K) { if (N < K) return 0; if (N < 0 || K < 0) return 0; return fac[N] * finv[K] * finv[N - K]; } #pragma endregion signed main() { int N, M; cin >> N >> M; int ans = M; int cnt = 1; while (M != 1 && cnt + 1 < N) { ans += ceil(M, 2); M = ceil(M, 2); cnt++; } cout << ans + (N - cnt) << endl; }