#include <cstdlib>
#include <iostream>
 
using namespace std;
 
int main()
{
	int n, x;
	cin >> n >> x;
	int a[n+1];
	for (int i = n; i >= 0; --i)
	{
		cin >> a[i];
	}
	int s = a[n];
	for (int i = 1; i <= n; ++i)
	{
		s *= x; 
		s += a[n-i];
	}
	cout << s << endl;
}