#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

int main(){
    vector<string> a(6);
    rep(i, 6) cin >> a[i];
    
    vector<string> b(6);
    rep(i, 6) b[i] = a[i];
    sort(all(b));
    b.erase(unique(all(b)), b.end());

    ll n = (ll)b.size();
    vector<ll> c(6);
    rep(i, 6) c[i] = lower_bound(all(b), a[i]) - b.begin();

    rep(bit, (1<<n)){
        bool ans1 = (bit>>c[0])&1;
        ans1 = ~ans1;
        ans1 = ans1 | ~((bit>>c[1])&1);
        ans1 = ~ans1;
        ans1 = ans1 | ~((bit>>c[2])&1);

        bool ans2 = (bit>>c[3])&1;
        ans2 = ~ans2;
        ans2 = ans2 | ~((bit>>c[4])&1);
        ans2 = ~ans2;
        ans2 = ans2 | ~((bit>>c[5])&1);

        bool ans = (~ans1) | (~ans2);

        if(ans){
            cout << "YES" << endl;
            return 0;
        }
    }

    cout << "NO" << endl;
}