#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	vector<string>s(6);
	vector<int>a(6);
	rep(i, 6)cin >> s[i];
	auto tmp = s;
	sort(all(tmp));
	tmp.erase(unique(all(tmp)), tmp.end());
	rep(i, 6) a[i] = lower_bound(all(tmp), s[i]) - tmp.begin();
	bool chk = false;
	rep(i, 2)rep(j, 2)rep(k, 2)rep(l, 2)rep(m, 2)rep(n, 2) {
		vector<int> v = { i,j,k,l,m,n };
		int x = !(v[a[0]] & v[a[1]]);
		int y = !(x & v[a[2]]);
		int s = !(v[a[3]] & v[a[4]]);
		int t = !(s & v[a[5]]);
		int val = !(y & t);
		if (1 == val)chk = true;
	}
	if (chk)cout << "YES" << endl;
	else cout << "NO" << endl;
	return 0;
}