#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  return b == 0 ? a : gcd(b, a % b);
}
long long int power(long long int x, long long int n) {
  long long int result = 1;
  while (n > 0) {
    if (n % 2 == 1) result = (result * x) % 1000000007;
    x = (x * x) % 1000000007;
    n = n / 2;
  }
  return result % 1000000007;
}
bool isPrime(long long int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
long long int inv(long long int a, long long int m) { return power(a, m - 2); }
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int n, m;
  cin >> n >> m;
  long long int sum = 0, a[n], i;
  for (i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  multiset<long long int> s;
  for (i = 0; i < n; i++) s.insert(sum - a[i]);
  long long int p = -1;
  while (s.size() > 0) {
    set<long long int>::iterator x = s.begin();
    long long int count = 0;
    long long int first = *x;
    while (count < m && first == *x && x != s.end()) {
      s.erase(x);
      x = s.begin();
      count++;
    }
    if (count < m) {
      p = min(first, sum);
      cout << power(m, p) % 1000000007;
      return 0;
    }
    s.insert(1ll + first);
  }
}
