#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;
    cin >> m;
    vector<tuple<ll,int,int>> ca;
    ca.reserve(3 * m);
    for(int i = 0; i < m; i++){
        int a, b, c;
        cin >> a >> b >> c;
        ca.emplace_back(((ll)(a) << 30) | b, 0, i);
        ca.emplace_back(((ll)(a) << 30) | c, 1, i);
        ca.emplace_back(((ll)(b) << 30) | c, 0, i);
    }
    sort(ca.begin(), ca.end());
    atcoder::dsu uf(2 * m);
    auto merge = [&](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);
    };
    for(int r = 0; r < ca.size(); ){
        int l = r;
        while(r < ca.size() && get<0>(ca[r]) == get<0>(ca[l])) r++;
        for(int i = l; i < r; i++){
            auto [key, d, v] = ca[i];
            for(int j = i + 1; j < r; j++){
                auto [key2, d2, u] = ca[j];
                merge(v, u, d ^ d2 ^ 1);
                if(uf.same(v, v + m)){
                    cout << "NO\n";
                    return 0;
                }
            }
        }
    }
    cout << "YES\n";
}