#include "migrations.h"
#include<bits/stdc++.h>
#define pb push_back
using namespace std;
const int maxn = 1e4 + 10;
int n;
vector < int > g[maxn];
int depth[maxn], recent, mx, best, still;
void dfs(int beg, int from, int dist)
{
depth[beg] = dist;
if(mx < depth[beg])
{
mx = dist;
best = beg;
}
for (auto nb: g[beg])
{
if(nb == from)continue;
dfs(nb, beg, dist+1);
}
}
int bit = 0;
int send_message(int N, int i, int Pi)
{
n = N;
g[Pi].pb(i);
g[i].pb(Pi);
dfs(0, -1, 0);
if(i == n-20)
{
recent = best;
still = 1;
int is = min(1, ((1 << bit) & recent));
bit ++;
return is;
}
else if(i > n-20)
{
if(best != recent && best == i)
{
still = 0;
return 2;
}
else if(!still)return 0;
else
{
int is = min(1, ((1 << bit) & recent));
bit ++;
return is;
}
}
else return 0;
}
std::pair<int, int> longest_path(std::vector<int> S)
{
n = S.size();
std::pair < int, int > p;
int last = 0;
for (int i = n-20; i < n; ++ i)
{
if(S[i] == 2)
last = i;
}
if(last == 0)
{
int b = 0;
for (int i = n-20; i < n; ++ i)
{
last += ((1 << b)) * S[i];
b ++;
}
}
return make_pair(0, last);
}
