#include <bits/stdc++.h>
using namespace std;
template <typename T>
void deb(initializer_list<T> l) {
  for (auto &e : l) cout << e << ' ';
  cout << '\n';
}
void solve() {
  int n;
  string o, p;
  cin >> n >> o >> p;
  vector<string> s;
  string a(n, 'a');
  string b(n, 'b');
  string c(n, 'c');
  s.push_back(a + b + c);
  s.push_back(a + c + b);
  s.push_back(b + a + c);
  s.push_back(b + c + a);
  s.push_back(c + a + b);
  s.push_back(c + b + a);
  a = "abc";
  do {
    string t = "";
    for (int i = n; i--;) t += a;
    s.push_back(t);
  } while (next_permutation(a.begin(), a.end()));
  cout << "YES\n";
  for (auto &e : s) {
    if (e.find(o) == string::npos && e.find(p) == string::npos) {
      cout << e << '\n';
      return;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int t = 1;
  while (t--) solve();
  return 0;
}
