#include <bits/stdc++.h>

using namespace std;

int main()
{
    string a, b, c;
    cin >> a >> b >> c;
    string ab = a + b;
    sort(ab.begin(), ab.end());
    sort(c.begin(), c.end());
    int n = ab.size(), m = c.size();
    if (n != m) {
        cout << "NO";
        return 0;
    }
    for (int i = 0; i < n; i++)
        if (ab[i] != c[i]) {
            cout << "NO";
            return 0;
        }
    cout << "YES";
    return 0;
}