#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int M;
int A[101010],B[101010],C[101010];

map<pair<int,int>,vector<int>> V;
map<pair<int,int>,int> D;

void dfs(pair<int,int> p,int dir) {
	
	if(D.count(p)) {
		if(D[p]!=dir) {
			cout<<"NO"<<endl;
			exit(0);
		}
		return;
	}
	D[{p.first,p.second}]=dir;
	D[{p.second,p.first}]=dir^1;
	if(V[p].size()>2) {
		cout<<"NO"<<endl;
		exit(0);
	}
	
	FORR(v,V[p]) {
		if(p.first==A[v]&&p.second==B[v]||p.first==B[v]&&p.second==C[v]||p.first==C[v]&&p.second==A[v]) {
			dfs({A[v],B[v]},dir);
			dfs({B[v],C[v]},dir);
			dfs({C[v],A[v]},dir);
		}
		else {
			dfs({A[v],B[v]},dir^1);
			dfs({B[v],C[v]},dir^1);
			dfs({C[v],A[v]},dir^1);
		}
	}
	
	
}


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>M;
	vector<int> Xs;
	FOR(i,M) {
		cin>>A[i]>>B[i]>>C[i];
		Xs.push_back(A[i]);
		Xs.push_back(B[i]);
		Xs.push_back(C[i]);
	}
	sort(ALL(Xs));
	FOR(i,M) {
		A[i]=lower_bound(ALL(Xs),A[i])-Xs.begin();
		B[i]=lower_bound(ALL(Xs),B[i])-Xs.begin();
		C[i]=lower_bound(ALL(Xs),C[i])-Xs.begin();
		V[{A[i],B[i]}].push_back(i);
		V[{B[i],C[i]}].push_back(i);
		V[{C[i],A[i]}].push_back(i);
		V[{B[i],A[i]}].push_back(i);
		V[{C[i],B[i]}].push_back(i);
		V[{A[i],C[i]}].push_back(i);
	}
	FORR2(a,b,V) if(D.count(a)==0) dfs(a,0);
	cout<<"YES"<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}