#include<cstdio>
#include<vector>
#include<ctime>
#include<algorithm>
#define vi vector<int>
using namespace std;
const int N=1e3+10;
int lca[N][12],dep[N],f[N];
mt19937 rnd;
int t[N*N];
void init(int x,int y)
{
	lca[x][0]=y;
	for(int i=1;i<=10;i++)
		lca[x][i]=lca[lca[x][i-1]][i-1];
	answer(x,y);
}
int get_dis(int x,int y)
{
	int s=dep[x]+dep[y];
	if(dep[x]<dep[y]) swap(x,y);
	for(int i=10;i>=0;i--)
		if(dep[lca[x][i]]>=dep[y]) x=lca[x][i];
	for(int i=10;i>=0;i--)
		if(lca[x][i]!=lca[y][i])
			x=lca[x][i],y=lca[y][i];
	if(x!=y) x=lca[x][0];
	return s-2*dep[x];
}
void solve(vi A,vi B)
{
	int m=A.size(),n=B.size(),cnt=0;
	if(m==0) return;
	if(n==1)
	{
		for(int x:A) init(x,B[0]);
		return;
	}
	else if(n==2)
	{
		vi v(1);
		v[0]=B[0];
		for(int x:A) if(ask(x,v)==1) init(x,v[0]);
		else init(x,B[1]);
		return;
	}
	vi v1(n/2);
	for(int i=1;i<m;i++) swap(A[i],A[rnd()%(i+1)]);
	for(int i=0;i<n/2;i++) v1[i]=B[i];
	for(int x:B) f[x]=v1.size();
	for(int x:B) for(int y:v1) f[x]+=get_dis(x,y);
	for(int x:B)
		if(!t[f[x]]) t[f[x]]=++cnt;
	vector<vi> v(cnt),a(cnt);
	for(int x:B) v[t[f[x]]-1].push_back(x);
	for(int x:A) a[t[ask(x,v1)]-1].push_back(x);
	for(int x:B) t[f[x]]=0;
	for(int i=0;i<cnt;i++) solve(a[i],v[i]);
}
vi v[N];
void solver(int n,int A,int B)
{
	int rt=rnd()%n+1;
	vi s(1);
	for(int i=1;i<=n;i++)
	{
		if(i==rt) continue;
		s[0]=i,dep[i]=ask(rt,s);
		v[dep[i]].push_back(i);
	}
	for(int x:v[1]) init(x,rt);
	for(int i=2;i<=n;i++)
	{
		if(v[i].empty()) break;
		solve(v[i],v[i-1]);
	}
}

implementer.cpp: In function ‘void regduj260135279::init()’:
implementer.cpp:32:22: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   32 |                 scanf("%d",&n);
      |                 ~~~~~^~~~~~~~~
implementer.cpp:45:30: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   45 |                         scanf("%d%d",&u,&v);
      |                         ~~~~~^~~~~~~~~~~~~~
answer.code:9:1: error: ‘mt19937’ does not name a type
    9 | mt19937 rnd;
      | ^~~~~~~
answer.code: In function ‘void init(int, int)’:
answer.code:16:9: error: ‘answer’ was not declared in this scope
   16 |         answer(x,y);
      |         ^~~~~~
answer.code: In function ‘void solve(std::vector<int>, std::vector<int>)’:
answer.code:43:33: error: ‘ask’ was not declared in this scope
   43 |                 for(int x:A) if(ask(x,v)==1) init(x,v[0]);
      |                                 ^~~
answer.code:48:42: error: ‘rnd’ was not declared in this scope; did you mean ‘rand’?
   48 |         for(int i=1;i<m;i++) swap(A[i],A[rnd()%(i+1)]);
      |                                          ^~~
      |                                          rand
answer.code:56:26: error: ‘ask’ was not declared in this scope
   56 |         for(int x:A) a[t[ask(x,v1)]-1].push_back(x);
      |                          ^~~
answer.code: In function ‘void solver(int, int, int)’:
answer.code:63:16: error: ‘rnd’ was not declared in this scope; did you mean ‘rand’?
   63 |         int rt=rnd()%n+1;
      |                ^~~
      |                rand
answer.code:68:31: error: ‘ask’ was not declared in this scope
   68 |                 s[0]=i,dep[i]=ask(rt,s);
      |                               ^~~