#include <bits/stdc++.h>
using namespace std;
const long long int N = 2e5 + 1;
const long long int mod = 1e9 + 7;
int main() {
  ios::sync_with_stdio(false);
  long long int n;
  string A, B, S = "abc";
  vector<string> V;
  cin >> n >> A >> B;
  do {
    string curr;
    for (int i = 0; i <= n - 1; i++) curr += S;
    V.push_back(curr);
    V.push_back(string(n, S[0]) + string(n, S[1]) + string(n, S[2]));
  } while (next_permutation(S.begin(), S.end()));
  for (auto str : V) {
    if (str.find(A) == string::npos && str.find(B) == string::npos) {
      cout << "YES\n" << str << "\n";
      return 0;
    }
  }
  cout << "NO\n";
  return 0;
}
