#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void rset();
void init_test();
void solve();
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed;
  cout.precision(20);
  init_test();
  return 0;
}
template <typename T>
void chmin(T& a, T b) {
  if (a > b) a = b;
}
template <typename T>
void chmax(T& a, T b) {
  if (a < b) a = b;
}
template <typename T>
void MACRO_rdv2_Init(long long n, T& t) {
  t.resize(n);
}
template <typename First, typename... Rest>
void MACRO_rdv2_Init(long long n, First& first, Rest&... rest) {
  first.resize(n);
  MACRO_rdv2_Init(n, rest...);
}
template <typename T>
void MACRO_rdv2_Scan(long long p, T& t) {
  std::cin >> t[p];
}
template <typename First, typename... Rest>
void MACRO_rdv2_Scan(long long p, First& first, Rest&... rest) {
  std::cin >> first[p];
  MACRO_rdv2_Scan(p, rest...);
}
template <typename T>
void wrv(const vector<T>& v) {
  for (long long(__ii) = (0); (__ii) < (((long long)v.size())); ++(__ii)) {
    if (__ii) cout << ' ';
    cout << v[__ii];
  }
  cout << '\n';
}
template <typename T>
void wrm(const vector<vector<T>>& v) {
  for (long long(__ii) = (0); (__ii) < (((long long)v.size())); ++(__ii)) {
    for (long long(__jj) = (0); (__jj) < (v[__ii].size()); ++(__jj)) {
      if (__jj) cout << ' ';
      cout << v[__ii][__jj];
    }
    cout << '\n';
  }
}
template <typename T>
void sc(T& x) {
  cin >> x;
}
template <typename Head, typename... Tail>
void sc(Head& head, Tail&... tail) {
  cin >> head;
  sc(tail...);
}
template <typename T>
void wr(const T& x) {
  cout << x << '\n';
}
template <typename Head, typename... Tail>
void wr(const Head& head, const Tail&... tail) {
  cout << head << ' ';
  wr(tail...);
}
template <typename T>
void wrf(const T& x) {
  cout << x << endl;
}
template <typename Head, typename... Tail>
void wrf(const Head& head, const Tail&... tail) {
  cout << head << ' ';
  wrf(tail...);
}
template <typename T>
void debug_out(const T& x) {
  cerr << x << '\n';
}
template <typename Head, typename... Tail>
void debug_out(const Head& head, const Tail&... tail) {
  cerr << head << ' ';
  debug_out(tail...);
}
template <typename... T>
void err(const T&... cod) {
  wr(cod...);
  exit(0);
}
const long long mod = 1e9 + 7;
void add_self(long long& x, long long y) {
  x += y;
  if (x >= mod) x -= mod;
}
void sub_self(long long& x, long long y) {
  x -= y;
  if (x < 0) x += mod;
}
long long add(long long x, long long y) {
  x += y;
  if (x >= mod) x -= mod;
  return x;
}
long long sub(long long x, long long y) {
  x -= y;
  if (x < 0) x += mod;
  return x;
}
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res % mod;
}
long long mult(long long x, long long y) { return (1LL * x * y) % mod; }
long long inv(long long x) { return powmod(x, mod - 2); }
long long divide(long long x, long long y) { return mult(x, inv(y)); }
void solve() {
  long long n, x;
  sc(n, x);
  vector<long long> a(n);
  for (long long(__ii) = (0); (__ii) < (n); ++(__ii)) cin >> a[__ii];
  long long s = accumulate(a.begin(), a.end(), 0LL);
  map<long long, long long> ma;
  for (long long(i) = (0); (i) < (n); ++(i)) {
    long long z = s - a[i];
    while (++ma[z] == x) ma.erase(z++);
  }
  long long z = min(ma.begin()->first, s);
  wr(powmod(x, z));
}
void init_test() {
  long long qq = 1;
  while (qq--) solve();
}
