#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001

int f(int a,int b){
	return (a&b)^1;
}

int main(){
	map<string,int> mp;
	vector<string> s(6);
	rep(i,6){
		cin>>s[i];
		mp[s[i]] = 0;
	}
	int ii = 0;
	for(auto &a:mp){
		a.second = ii;
		ii++;
	}
	
	rep(i,1<<i){
		vector<int> p(6);
		rep(j,6){
			p[j] = (i>>mp[s[j]])&1;
		}
		
		if(f(f(f(p[0],p[1]),p[2]),f(f(p[3],p[4]),p[5]))){
			cout<<"YES"<<endl;
			return 0;
		}
		
	}
	cout<<"NO"<<endl;
	
	
	return 0;
}