#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int m, a, b, c;
    cin >> m;
    vector<pair<ll,int>> ca(3 * m);
    for(int i = 1, ci = 0; i <= m; i++){
        cin >> a >> b >> c;
        ca[ci++] = {(ll)(a) << 30 | b, i};
        ca[ci++] = {(ll)(b) << 30 | c, i};
        ca[ci++] = {(ll)(a) << 30 | c, -i};
    }
    sort(ca.begin(), ca.end());
    atcoder::dsu uf(2 * ++m);
    auto add = [&](int u, int v, int d){
        if(d >= 0)uf.merge(u, v), uf.merge(u + m, v + m);
        else uf.merge(u + m, v), uf.merge(u, v + m);
        if(uf.same(u, u + m)) cout << "NO\n", exit(0);
    };
    for(int i = 0; i + 1 < ca.size(); i++){
        auto [k1, v] = ca[i];
        if(i + 2 < ca.size() && k1 == ca[i + 2].first) cout << "NO\n", exit(0);
        auto [k2, u] = ca[i + 1];
        if(k1 == k2)add(abs(v), abs(u), v ^ u ^ -1);
    }
    cout << "YES\n";
}