#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using Graph = vector<vector<ll>>;
using vi = vector<int>;
using vl = vector<long>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvl = vector<vl>;
using vvll = vector<vll>;
using vs = vector<string>;
using vc = vector<char>;
using vvc = vector<vc>;
using pll = pair<long long, long long>;
using vpll = vector<pll>;
using mint = modint1000000007;
const long double EPS = 1e-18;
const long long INF = 1e18;
const long double PI = acos(-1.0L);
#define reps(i, a, n) for (ll i = (a); i < (ll)(n); i++)
#define rep(i, n) for (ll i = (0); i < (ll)(n); i++)
#define rrep(i, n) for (ll i = (1); i < (ll)(n + 1); i++)
#define repd(i, n) for (ll i = n - 1; i >= 0; i--)
#define rrepd(i, n) for (ll i = n; i >= 1; i--)
#define ALL(n) begin(n), end(n)
#define IN(a, x, b) (a <= x && x < b)
#define INIT                          \
    std::ios::sync_with_stdio(false); \
    std::cin.tie(0);
template <class T>
inline T CHMAX(T& a, const T b) {
    return a = (a < b) ? b : a;
}
template <class T>
inline T CHMIN(T& a, const T b) {
    return a = (a > b) ? b : a;
}
ll NAND(ll a, ll b) { return ~(a & b); }
ll gate(vll A) {
    return NAND((NAND((NAND(A[0], A[1])), A[2])),
                (NAND((NAND(A[3], A[4])), A[5])));
}
int main() {
    vll A;
    map<string, ll> ma;
    ll res = 0;
    rep(i, 6) {
        string s;
        cin >> s;
        if (!ma.count(s)) {
            ma[s] = res;
            res++;
        }
        A.push_back(ma[s]);
    }
    ll ans = 0;
    rep(bit, (1ll << 6)) {
        vll B;
        rep(i, 6) {
            if (bit & (1ll << A[i])) {
                B.push_back(1);
            } else {
                B.push_back(0);
            }
        }
        CHMAX(ans, gate(B));
    }
    if (ans) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
}