#include<bits/stdc++.h>
#define F first
#define S second
#define int long long
#define double long double
using namespace std;
typedef pair<int,int> P;
typedef pair<int,P> iP;
typedef pair<P,int> Pi;
typedef pair<P,P> PP;
double eps=1e-8;
int mod=1e9+7;
int inf=1LL<<55;
priority_queue<P,vector<P>,greater<P> > pq;
template <typename T>
int Count(const vector<T> &v, T l,T r){
//counting [l,r]
auto L = lower_bound(v.begin(), v.end(), l );
auto R = upper_bound(v.begin(), v.end(), r );
// [l,r) change upper -> lower
return R-L;
}
signed main(){
int a[3],b[3];
int cnt[5]={},mx=0;
for(int i=0;i<3;i++){
cin>>a[i]>>b[i];
cnt[a[i]]++,cnt[b[i]]++;
}
for(int i=1;i<=4;i++)mx=max(cnt[i],mx);
cout<<(mx>2?"NO":"YES")<<endl;
return 0;
}