#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
using P=pair<ll,ll>;
using V=vector<ll>;
#define rep(i,n) for(ll i=0;i<n;i++)
#define REP(i,n) for(ll i=1;i<=n;i++)

int nd(int x,int y){
    if(x&&y) return 0;
    else return 1;
}

int main(){
    vector<string> s(6),t;
    rep(i,6) cin >> s[i];
    t=s;
    sort(t.begin(),t.end());
    V a(6);
    rep(i,6) rep(j,6) if(s[i]==t[j]) a[i]=j;

    bool flag=false;
    rep(i,64){
        V b(6);
        rep(j,6) b[j]=(i>>a[j])&1;
        if(nd(nd(nd(b[0],b[1]),b[2]),nd(nd(b[3],b[4]),b[5]))) flag=true;
    }
    
    if(flag) cout << "YES" << endl;
    else cout << "NO" << endl;

}