#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s1, s2;
  cin >> s1 >> s2;
  string s = "abc";
  vector<string> v;
  do {
    string ss = "";
    for (int i = 0; i < n; i++) ss += s;
    v.push_back(ss);
    ss = "";
    for (int i = 0; i < n; i++) ss += s[0];
    for (int i = 0; i < n; i++) ss += s[1];
    for (int i = 0; i < n; i++) ss += s[2];
    v.push_back(ss);
  } while (next_permutation(s.begin(), s.end()));
  for (auto it : v) {
    if (it.find(s1) == string::npos && it.find(s2) == string::npos) {
      cout << "YES" << endl;
      cout << it << endl;
      return 0;
    }
  }
}
