#include <vector>
using namespace std;
constexpr int N = 1e4;
int checkpoint;
pair<int, int> maxopt = {0, 0};
int depth[N] = {0};
bool highly[N];
void init(int n) {
maxopt = {0, 0};
depth[0] = 0;
}
int send_message(int n, int i, int p) {
if (i == n - 14) {
checkpoint = maxopt.second;
}
highly[i] = false;
depth[i] = depth[p] + 1;
if (depth[i] > maxopt.first) {
maxopt.first = depth[i];
maxopt.second = i;
highly[i] = true;
}
if (i < n - 14) {
return 0;
}
if (i < n - 7) {
return 1 + ((checkpoint >> 2 * (i - (n - 14))) & 3);
}
int d = n - 1 - i;
return 1 + highly[n - 1 - 2 * d - 1] + 2 * highly[n - 1 - 2 * d];
}
pair<int, int> longest_path(vector<int> S) {
int n = S.size();
int opt = 0;
for (int i = n - 14; i < n - 7; i++) {
opt |= (S[i] - 1) << 2 * (i - (n - 14));
}
for (int i = n - 7; i < n; i++) {
int d = n - 1 - i;
if ((S[i] - 1) & 1)
opt = n - 1 - 2 * d - 1;
if ((S[i] - 1) & 2)
opt = n - 1 - 2 * d;
}
return {0, opt};
}
