#include "simurgh.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define fastio ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
typedef pair < long long, long long > pll;
typedef pair < int, int > pii;
typedef unsigned long long ull;
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;
typedef long long ll;
typedef double db;
typedef tree < int, null_type, less < int >, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
const int inf = 1e9, maxn = 2e5 + 48, mod = 998244353, N = 512;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 300;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = acos(-1);
const ll INF = 1e18;
vi g[N];
int id[N][N], m, d[N], par[N], p[N*N];
set < int > q, qq, bad, good;
bool was[N];
void dfs (int v) {
was[v] = 1;
for (auto to : g[v])
if (!was[to]) {
q.insert(id[v][to]);
d[to] = d[v] + 1;
dfs(to);
par[to] = v;
}
}
int get (int x) {
vi cur;
for (auto y : qq)
if (y != x)
cur.pb(y);
for (auto y : q)
if (!qq.count(y))
cur.pb(y);
return count_common_roads(cur);
}
vi find_roads(int n, vi u, vi v) {
m = sz(v);
for (int i = 0; i < m; ++i) {
g[v[i]].pb(u[i]);
g[u[i]].pb(v[i]);
id[v[i]][u[i]] = id[u[i]][v[i]] = i;
}
dfs(0);
for (int i = 0; i < m; ++i)
p[i] = i;
random_shuffle(p, p + m);
for (int j = 0; j < m; ++j) {
int i = p[j];
if (q.count(i) || bad.count(i) || good.count(i))
continue;
qq.clear();
qq.insert(i);
if (d[v[i]] < d[u[i]])
swap(v[i], u[i]);
int Good = -1, Bad = -1;
while (v[i] != u[i]) {
qq.insert(id[v[i]][par[v[i]]]);
if (bad.count(id[v[i]][par[v[i]]]))
Bad = id[v[i]][par[v[i]]];
if (good.count(id[v[i]][par[v[i]]]))
Good = id[v[i]][par[v[i]]];
v[i] = par[v[i]];
}
vpii res;
for (auto x : qq) {
if (bad.count(x) || good.count(x))
continue;
res.pb(mp(get(x), x));
}
sort(all(res));
if (res[0].f == res.back().f) {
if (Bad != -1) {
if (get(Bad) == res.back().f) {
for (auto y : qq)
if (!good.count(y))
bad.insert(y);
} else {
for (auto y : qq)
if (!bad.count(y))
good.insert(y);
}
} else if (Good != -1) {
if (get(Good) == res.back().f) {
for (auto y : qq)
if (!bad.count(y))
good.insert(y);
} else {
for (auto y : qq)
if (!good.count(y))
bad.insert(y);
}
} else {
for (auto y : qq)
if (!good.count(y))
bad.insert(y);
}
} else {
for (auto y : res)
if (y.f == res[0].f)
good.insert(y.s);
else
bad.insert(y.s);
}
}
vi ans;
for (int i = 0; i < m; ++i)
if (!bad.count(i))
good.insert(i);
for (auto x : good)
ans.pb(x);
return ans;
}
