#include "migrations.h"
#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> adj;
int send_message(int n, int i, int pi) {
if (i == 1) adj.resize(n);
adj[i].push_back(pi);
adj[pi].push_back(i);
if (i < n - 1) return 0;
vector<bool> vis(n, false);
vis[0] = true;
stack<pair<int, int>> s;
s.push({0, 0});
int message, ans = -1;
while (!s.empty()) {
auto [at, d] = s.top();
s.pop();
if (d > ans) ans = d, message = at;
for (int to : adj[at]) {
if (!vis[to]) {
vis[to] = true;
s.push({to, d + 1});
}
}
}
return message - 5;
}
pair<int, int> longest_path(vector<int> s) {
return {0, s[s.size() - 1] + 5};
}
