#include <bits/stdc++.h>
using namespace std;
int main() {
  string x, y, z;
  cin >> x;
  cin >> y;
  cin >> z;
  x += y;
  sort(x.begin(), x.end());
  sort(z.begin(), z.end());
  if (x.length() != z.length())
    cout << "NO"
         << "\n";
  else {
    for (int i = 0; i < x.length(); i++) {
      if (x[i] != z[i]) {
        cout << "NO"
             << "\n";
        return 0;
      }
    }
    cout << "YES"
         << "\n";
  }
  return 0;
}
