#include<stdio.h>
#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using namespace std;

int main()
{
    long long n, k, cnt, r, mod = 0;
    cin >> n >> k;
    vector<long long> a(n);
    for (int i = 0; i < n; i++){
        cin >> a[i];
        mod += a[i];
    }
    for (int i = 0; i < n; i++){
        r *= k;
        r += a[i];
        r %= mod;
    }
    cout << r << endl;
}