#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s, t;
  cin >> s >> t;
  string ans;
  cout << "YES" << endl;
  if (s[0] == s[1] || t[0] == t[1]) {
    if (s[0] == s[1] && t[0] == t[1]) {
      for (int i = 0; i < n; i++) {
        cout << "abc";
      }
    } else {
      if (s[0] == s[1]) swap(s, t);
      if (t[0] == s[0]) {
        for (int i = 0; i < n; i++) {
          cout << s[1];
        }
        char c;
        if ('a' != s[0] && 'a' != s[1])
          c = 'a';
        else if ('b' != s[0] && 'b' != s[1])
          c = 'b';
        else
          c = 'c';
        for (int i = 0; i < n; i++) {
          cout << c << s[0];
        }
      } else if (t[0] == s[1]) {
        for (int i = 0; i < n; i++) {
          cout << s[0];
        }
        char c;
        if ('a' != s[0] && 'a' != s[1])
          c = 'a';
        else if ('b' != s[0] && 'b' != s[1])
          c = 'b';
        else
          c = 'c';
        for (int i = 0; i < n; i++) {
          cout << c;
          cout << s[1];
        }
      } else {
        for (int i = 0; i < n; i++) {
          cout << t[0];
          cout << s[1];
        }
        for (int i = 0; i < n; i++) cout << s[0];
      }
    }
  } else {
    if (s[0] == t[0]) {
      for (int i = 0; i < n; i++) cout << s[1];
      char c;
      if ('a' != s[0] && 'a' != s[1])
        c = 'a';
      else if ('b' != s[0] && 'b' != s[1])
        c = 'b';
      else
        c = 'c';
      for (int i = 0; i < n; i++) cout << c;
      for (int i = 0; i < n; i++) cout << s[0];
    } else if (s[0] == t[1] || t[0] == s[1]) {
      if (t[0] == s[1]) swap(s, t);
      char c;
      if ('a' != s[0] && 'a' != s[1])
        c = 'a';
      else if ('b' != s[0] && 'b' != s[1])
        c = 'b';
      else
        c = 'c';
      for (int i = 0; i < n; i++) cout << s[0];
      for (int i = 0; i < n; i++) cout << c;
      for (int i = 0; i < n; i++) cout << s[1];
    } else {
      for (int i = 0; i < n; i++) cout << t[1];
      for (int i = 0; i < n; i++) cout << s[0];
      char c;
      if ('a' != s[0] && 'a' != s[1])
        c = 'a';
      else if ('b' != s[0] && 'b' != s[1])
        c = 'b';
      else
        c = 'c';
      for (int i = 0; i < n; i++) cout << c;
    }
  }
  return 0;
}
