#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 50;
int main() {
  int n;
  string s, t;
  cin >> n >> s >> t;
  string abc = "abc";
  vector<string> res;
  do {
    string cur;
    for (int i = 1; i <= n; i++) cur += abc;
    res.push_back(cur);
    res.push_back(string(n, abc[0]) + string(n, abc[1]) + string(n, abc[2]));
  } while (next_permutation(abc.begin(), abc.end()));
  for (auto str : res) {
    if (str.find(s) == string::npos && str.find(t) == string::npos) {
      cout << "YES" << endl << str << endl;
      return 0;
    }
  }
  cout << "NO" << endl;
  return 0;
}
