#include <bits/stdc++.h>
#include "simurgh.h"
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define st first
#define nd second
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
int inf=1000000007;
ll infl=1000000000000000007;
const int N=507,M=507*507;
vector<pair<int,int>>G[N];
int odw[N],c;
int o[N],id[N];
vector<int>st;
int val[M];
void dfs(int v)
{
odw[v]=++c;
for(auto [u,i]:G[v])
{
if(!odw[u])
{
o[u]=v;
id[u]=i;
st.pb(i);
dfs(u);
}
}
}
/*int Find(int v)
{
if(r[v]==v) return v;
return r[v]=Find(r[v]);
}
int Union(int u,int v)
{
u=Find(u),v=Find(v);
r[u]=v;
}
int r[N];
vector<int>get(vector<int>W)
{
}*/
int get(int x)
{
vector<int>Q;
for(auto y:st) if(y!=x) Q.pb(y);
return count_common_roads(Q);
}
void dfs1(int v)
{
odw[v]=++c;
for(auto [u,i]:G[v])
{
if(!odw[u]) dfs1(u);
else if(odw[u]<odw[v]&&u!=o[v])
{
vector<int>V={i};
st.pb(i);
int p=-1,x=v;
while(x!=u)
{
if(val[id[x]]) p=id[x];
else V.pb(id[x]);
x=o[x];
}
if(p==-1)
{
vector<pair<int,int>>W;
int mx=-inf;
for(auto x:V)
{
int k=get(x);
mx=max(mx,k);
W.pb({k,x});
}
for(auto [k,x]:W)
{
if(k<mx) val[x]=2;
else val[x]=1;
}
}
else
{
for(auto x:V)
{
int c1=get(p),c2=get(x);
if(c1==c2) val[x]=val[p];
else if(c1<c2) val[x]=1;
else val[x]=2;
}
}
st.pop_back();
}
}
if(!val[id[v]]) val[id[v]]=2;
}
vector<int>find_roads(int n,vector<int>U,vector<int>V)
{
int m=sz(U);
for(int i=0;i<m;i++)
{
G[U[i]].pb({V[i],i});
G[V[i]].pb({U[i],i});
}
dfs(0);
memset(odw,0,sizeof odw);
dfs1(0);
vector<int>ans;
for(int i=0;i<m;i++) if(val[i]==2) ans.pb(i);
return ans;
}
/*
int main()
{
vector<int>X=find_roads(4,{0, 0, 0, 1, 1, 2},{1, 2, 3, 2, 3, 3});
return 0;
}*/
