import java.io.PrintStream;
import java.util.Scanner;


public class Y444 {
	Scanner in = new Scanner(System.in);
	PrintStream out = new PrintStream(System.out);

	long MOD = 1000000007;
	
	
	Y444() throws Exception {
		int n = in.nextInt();
		long c = in.nextLong();
		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = in.nextInt();
		}
		
		Matrix m = new Matrix();
		for (int i = 0; i < n; i++) {
			m.a[i][i] = a[i];
			m.a[i+n][i+n] = a[i];
			for (int j = 0; j < i; j++) {
				m.a[i+n][j] = a[i];
				m.a[i+n][j+n] = a[i];
			}
		}
				
		Matrix power = m.pow(c - 1);
		long ans = 0;
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				ans = (ans + a[j] * power.a[i+n][j]) % MOD;
			}
		}

		power=m.mul(m);
		out.println(ans);
	}

	public static void main(String argv[]) throws Exception {
		new Y444();
	}

	
	
	class Matrix {
		long[][] a = new long[160][160];

		Matrix mul(Matrix that) {
			Matrix ret = new Matrix();
			for (int i = 0; i < a.length; i++) {
				for (int j = 0; j < a.length; j++) {
					for (int k = 0; k < a.length; k++) {
						ret.a[i][k] = (ret.a[i][k] + a[i][j] * that.a[j][k]) % MOD;
					}
				}
			}
			return ret;
		}

		Matrix pow(long p) {
			Matrix ret = new Matrix();
			Matrix x = this;
			
			for (int i = 0; i < a.length; i++) {
				ret.a[i][i] = 1;
			}
			
			while (p > 0) {
				if ((p & 1) == 1) {
					ret = x.mul(ret);
				}
				x = x.mul(x);
				p >>= 1;
			}
			
			return ret;
		}
	}
}