#include <bits/stdc++.h>
using namespace std;
long long n, ar[1000001], mod = 1e9 + 7, factorialn = 1;
long long ans;
long long binpow(long long a, long long b) {
  if (b == 1) return a;
  if (b % 2 == 1)
    return a * 1ll * binpow(a, b - 1) % mod;
  else {
    long long h = binpow(a, b / 2);
    return h * 1ll * h % mod;
  }
}
long long ok(long long a, long long b) {
  long long h;
  h = a * 1ll * factorialn % mod;
  return h * 1ll * binpow(b, mod - 2) % mod;
}
int main() {
  cin >> n;
  for (long long i = 1; i <= n; i++)
    cin >> ar[i], factorialn = factorialn * 1ll * i % mod;
  sort(ar + 1, ar + n + 1);
  long long x = 1;
  for (long long i = 2; i <= n + 1; i++) {
    if (ar[i] != ar[i - 1]) {
      if (n - (i - x - 1) != x)
        ans = (ans + ok(x, n - (i - x - 1)) * 1ll * ar[i - 1]) % mod;
      x = 1;
    } else
      x++;
  }
  cout << ans;
  return 0;
}
