/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner scanIn=new Scanner(System.in); 
		int n, x;
 
		n = scanIn.nextInt();
		x = scanIn.nextInt();
 
		int a[] = new int[n + 1];
 
		for (int i = n; i >= 0; --i) {
			a[i] = scanIn.nextInt(); //enter values of array
		}
 
		int s = a[n];
 
		for (int i = 1; i <= n; ++i) {
			s *= x; 
			s += a[n - i];
		}
 
		System.out.println("S = " + s);
	}
}

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

MQo1CjIKMQ==

1
5
2
1