#define LOCAL #ifdef LOCAL #define _GLIBCXX_DEBUG #endif #include using namespace std; #define rep(i,x) for(ll i = 0; i < (ll)(x); i++) #define rrep(i,x) for(ll i = (ll)(x)-1;0 <= i; i--) #define reps(i,x) for(ll i = 1; i < (ll)(x)+1; i++) #define rreps(i,x) for(ll i = (ll)(x); 1 <= i; i--) #define all(x) (x).begin(), (x).end() typedef long long ll; typedef long double ld; typedef pair Pll; typedef vector vl; typedef vector vvl; typedef vector vvvl; constexpr ll INF = numeric_limits::max()/4; constexpr ll n_max = 2e5+10; #define int ll template string to_string(pair p); string to_string(const string &s) {return '"' + s + '"';} string to_string(const char c) {return to_string((string) &c);} string to_string(bool b) {return (b ? "true" : "false");} template string to_string(bitset v){ string res = ""; for(size_t i = 0; i < N; i++) res += static_cast('0' + v[i]); return res; } template string to_string(A v) { bool first = true; string res = "{"; for(const auto &x : v) { if(!first) res += ", "; first = false; res += to_string(x); } res += "}"; return res; } template string to_string(pair p){return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";} void debug_out() {cerr << endl;} template void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...); } #ifdef LOCAL #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__) #else #define debug(...) 42 #endif signed main(){ cin.tie(nullptr); ios::sync_with_stdio(false); ll n,k; cin >> n >> k; ll ans = 0; if(n & 1){ if(k & 1){ ll t = (k + 1) / 2; ans = min(n, 2 * t); } else ans = min(k + 1, n); } else{ if(k & 1){ ll t = (k + 1) / 2; ans = min(n / 2, 2 * t); } else ans = min(k + 1, n / 2); } cout << ans << endl; }