#include <vector>
#include "communication.h"
typedef long long ll;
using namespace std;
struct interval {
ll l, r;
interval(ll l, ll r) : l(l), r(r) {}
bool contains(ll x) {
return l <= x && x < r;
}
ll length() {
return r - l;
}
interval shrink(ll o, ll s) {
return interval(min(r, l + o), min(r, l + o + s));
}
};
vector<interval> splitIntervals(vector<interval> c, ll o, ll s) {
vector<interval> r;
for (interval &it : c) {
if (s > 0 && it.length() - o > 0)
r.push_back(it.shrink(o, s));
s -= max(0LL, min(s, it.length() - o));
o -= min(o, it.length());
}
return r;
}
bool contains(vector<interval> c, ll x) {
for (interval &it : c)
if (it.contains(x))
return true;
return false;
}
struct state {
ll s = 0;
vector<interval> c;
state() {}
state(ll N): s(N) {
c.emplace_back(1, N + 1);
}
state(vector<vector<interval>> &cs) {
for (vector<interval> &c : cs)
add(c);
}
void add(interval it) {
s += it.length();
c.push_back(it);
}
void add(vector<interval> &c) {
for (interval &it : c)
add(it);
}
vector<vector<interval>> split() {
vector<vector<interval>> r;
ll s1 = s / 3, s2 = (s - s1) / 2, s3 = s - s1 - s2;
r.push_back(splitIntervals(c, 0, s1));
r.push_back(splitIntervals(c, s1, s2));
r.push_back(splitIntervals(c, s1 + s2, s3));
return r;
}
ll size() {
return s;
}
vector<ll> remaining() {
vector<ll> r;
for (interval &it : c)
for (ll v = it.l; v < it.r; v++)
r.push_back(v);
return r;
}
};
std::pair<int, int> solve(int N, int X = -1) {
state s(N);
while (s.size() > 2) {
vector<vector<interval>> c = s.split();
int b1 = 1, b2;
for (int i = 0; i < 2 && b1; i++)
b1 = X != -1 ? send(contains(c[0], X) || contains(c[1], X)) : receive();
if (!b1)
b2 = X != -1 ? send(contains(c[0], X)) : receive();
c.erase(c.begin() + (b1 ? 2 : (b2 ? 1 : 0)));
s = state(c);
}
vector<ll> r = s.remaining();
return {r[0], r.back()};
}
void encode(int N, int X) {
solve(N, X);
}
std::pair<int, int> decode(int N) {
return solve(N);
}
