#include <bits/stdc++.h>
using namespace std;
using vb = vector<bool>;
const int N = 1025, L = 31, Q = 66;
vb send_packet(vb A);
void send_message(vb M, vb C) {
vector<vb> R(Q, vb(L, 0));
M.resize(N, M.back() ^ 1);
int k = 0;
for (int i = 0; i < L; i++) if (C[i] == 0) {
int c = 1;
while (C[(i + c) % 31] == 1) c++;
R[c - 1][i] = 1;
for (int j = c; j < Q; j++) R[j][i] = M[k++];
}
for (int i = 0; i < Q; i++) send_packet(R[i]);
}
vb receive_message(vector<vb> R) {
vector<int> f(L);
for (int i = 0; i < L; i++) {
int c = 1;
for (int j = 0; j < Q; j++) {
if (R[j][i] == 1) break;
c++;
}
f[i] = (i + c) % 31;
}
vb M(N);
int k = 0;
for (int i = 0; i < L; i++) {
bool flag = true;
int p = i;
for (int t = 0; t < 16; t++) {
p = f[p], flag &= (p == i) == (t == 15);
}
if (!flag) continue;
flag = false;
for (int j = 0; j < Q; j++) {
if (flag) M[k++] = R[j][i];
else flag = R[j][i];
}
}
bool b = M.back();
while (M.back() == b) M.pop_back();
return M;
}
