#include "migrations.h"
#include <bits/stdc++.h>
using namespace std;
const int maxn = 10000;
int par[maxn];
int ret;
int mxdep;
void dfs(int st, vector<int>g[], int p, int dep){
if(dep>mxdep){
ret=st;
mxdep=dep;
}
for(int i : g[st]){
if(i==p)
continue;
dfs(i,g,st,dep+1);
}
}
int send_message(int n, int i, int Pi) {
par[i]=Pi;
if(i==n-1){
//it is done.
vector<int>g[n];
for(int i = 1;i<n;i++){
g[i].push_back(par[i]);
g[par[i]].push_back(i);
}
dfs(0,g,-1,0);
return ret-2;
}
return 0;
}
pair<int, int> longest_path(vector<int> S) {
return {0,S[((int)S.size())-1]+2};
}
