/* -*- coding: utf-8 -*-
 *
 * 1343.cc:  No.1343 Dividing Digit - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;

/* typedef */

typedef long long ll;

/* global variables */

int as[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);

  int asum = 0;
  for (int i = n - 1; i >= 0; i--)
    scanf("%d", as + i), asum += as[i];

  int sum = 0, e = 1;
  for (int i = 0; i < n; i++) {
    sum = (sum + (ll)as[i] * e % asum) % asum;
    e = (ll)e * k % asum;
  }

  printf("%d\n", sum);
  return 0;
}