#include <bits/stdc++.h>
using namespace std;
long long res;
int x;
int n, mas[100002];
long long sum;
map<long long, long long> m;
long long power(long long a, long long b) {
  long long res = 1;
  if (b == 0) return 1;
  if (b % 2 == 0) {
    long long c = power(a, b / 2) % 1000000007;
    return (c * c) % 1000000007;
  } else
    return (power(a, b - 1) * a) % 1000000007;
}
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cin >> n >> x;
  for (int i = 0; i < n; ++i) {
    cin >> mas[i];
    sum += mas[i];
  }
  for (int i = 0; i < n; ++i) m[sum - mas[i]]++;
  long long countt = 1, minn = 1000000000009;
  int j = 0;
  for (map<long long, long long>::iterator it = m.begin(); it != m.end();
       ++it) {
    if ((*it).second % x != 0) {
      cout << power(x, min(sum, (*it).first));
      return 0;
    }
    m[(*it).first + 1] += (*it).second / x;
    minn = (*it).first + 1;
  }
  cout << power(x, min(minn, sum));
  return 0;
}
