Untitled

#include <bits/stdc++.h>
#define endl '\n'
#define maxn 1005
#define TASK bai1
#define For(i,a,b) for ( int i = a; i <= b; i++ )
#define Ford(i,a,b) for ( int i = a; i >= b; i-- )
#define MOD 10000000

using namespace std;

struct wood {
    double dai ;
    double rong ;
} ;

wood go[10] ;

void inp() {
    For(i,1,6) {
        cin >> go[i].dai >> go[i].rong ;
        if ( go[i].dai < go[i].rong ) swap(go[i].dai, go[i].rong) ;
    }
}

bool ss(wood x, wood y) {
    if ( x.dai != y.dai ) return x.dai < y.dai;
    if ( x.rong != y.rong ) return x.rong < y.rong ;
    return 0 ;
}

bool check(int i,int j) {
    return ( go[i].dai == go[j].dai && go[i].rong == go[j].rong ) ;
}

void solve() {
    sort(go+1,go+6+1,ss) ;
    int dem = 0;
    if ( check(1,2) + check(3,4) + check(5,6) == 3 ) cout << "YES" ;
        else cout << "NO" ;
}

int main()
{
    ios_base:: sync_with_stdio(0);
    cin.tie(0);
    if(fopen("bai1.inp","r")){
        freopen("bai1.inp","r",stdin);
    }
    inp();
    solve();
}