#include <bits/stdc++.h>
using namespace std;
bool B[6];
bool nd(bool a, bool b) {
    return !(a&&b);
}
bool ok() {
    return nd(nd(nd(B[0], B[1]), B[2]), nd(nd(B[3], B[4]), B[5]));
}
int main () {
    int A[6];
    map<string, int> mp;
    int c = 0;
    for (int i = 0; i < 6; i ++) {
        string s;
        cin >> s;
        if (mp.find(s) != mp.end()) {
            A[i] = mp[s];
        } else {
            A[i] = c;
            mp[s] = c;
            c ++;
        }
    }
    for (int i = 0; i < (1 << 6); i ++) {
        for (int j = 0; j < 6; j ++) {
            B[j] = (i >> (A[j])) & 1;
        }
        if (ok()) {
            cout << "YES" << endl;
            return 0;
        }
    }
    cout << "NO" << endl;
}