#include <bits/stdc++.h>
using namespace std;
const int ERR = -1;
const long double EPS = 1e-10;
void alert(string str) {
  cout << str;
  exit(0);
}
int gcd(int a, int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
int main() {
  ios_base::sync_with_stdio(0);
  string a, b, c;
  cin >> a >> b >> c;
  map<char, int> f, s;
  for (int i = 0; i < (int)a.size(); ++i) ++f[a[i]];
  for (int i = 0; i < (int)b.size(); ++i) ++f[b[i]];
  for (int i = 0; i < (int)c.size(); ++i) ++s[c[i]];
  if (f == s) alert("YES");
  alert("NO");
  return 0;
}
