#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e15;
const long long MAX = 2e6 + 7;
const long long MOD = 1000000007;
const long double PI = 3.141592653589793238463;
long long i, j, k, t, n, q, l, r, mid;
string s, st, res, ans;
vector<string> v;
void solve() {
  cin >> n;
  cin >> s >> st;
  ans = "abc";
  do {
    res = "";
    for (long long i = 0; i < n; i++) res += ans;
    v.push_back(res);
    v.push_back(string(n, ans[0]) + string(n, ans[1]) + string(n, ans[2]));
  } while (next_permutation(ans.begin(), ans.end()));
  for (auto x : v) {
    if (x.find(s) == string::npos && x.find(st) == string::npos) {
      cout << "YES"
           << "\n";
      cout << x << "\n";
      return;
    }
  }
  cout << "NO"
       << "\n";
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
  return 0;
}
