/*input
*/
/**
Author: Kristopher Paul
Date Created: 15-05-2019
Contest Name:
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**/
#include<bits/stdc++.h>
#define ll long long
//#define int ll
#define pb push_back
#define INF 0x3f3f3f3f //0x3f3f3f3f = 63
#define MOD 1000000009
#define mp make_pair
const double PI=3.141592653589793238462643383279502884197169399375105820974944;
#define REP(i,n) for (int i = 0; i < n; i++)
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define REPD(i,n) for (int i = n-1; i >= 0; i--)
#define FORD(i,a,b) for (int i = a; i >= b; i--)
#define remax(a,b) a = max(a,b)
#define remin(a,b) a = min(a,b)
#define umap unordered_map
#define pii pair<int,int>
#define F first
#define S second
#define mii map<int,int>
#define vi vector<int>
#define vvi vector<vi>
#define itr :: iterator it
#define all(v) v.begin(),v.end()
#define WL(t) while(t--)
#define gcd(a,b) __gcd((a),(b))
#define lcm(a,b) ((a)*(b))/gcd((a),(b))
#define out(x) cout << #x << " is " << x << endl
#define FastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
using namespace std;
ll ModExp(ll x,ll y,ll m){
ll res = 1;
x = x % m;
while (y > 0)
{
if (y & 1)
res = (res*x) % m;
y = y>>1;
x = (x*x) % m;
}
return res;
}
set<int> nei[1505];
set<pii> edg;
void initialize(int n){
FOR(i,1,n+1){
FOR(j,1,n+1){
if(i == j){
continue;
}
nei[i].insert(j);
}
}
}
int hasEdge(int u, int v){
u++;
v++;
if(nei[u].size() == 1 || nei[v].size() == 1){
nei[u].erase(v);
nei[v].erase(u);
edg.insert({u,v});
edg.insert({v,u});
return 1;
}
if(edg.find({u,v}) != edg.end()){
return 1;
}
nei[u].erase(v);
nei[v].erase(u);
return 0;
}
/*
void solve(){
int n;
cin >> n;
initialize(n);
FOR(i,0,(n*(n-1))/2){
int u,v;
cin >> u >> v;
cout << hasEdge(u,v) << endl;
}
system("pause");
}
signed main(){
FastIO;
int t = 1;
// cin >> t;
WL(t){
solve();
}
}*/
