#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np
MOD = 10 ** 9 + 7

N, C, *A = map(int, read().split())
mat = np.zeros((N, N), np.int64)
for i, x in enumerate(A):
    mat[i, : i + 1] = x
mat.flags.writeable = False


def mult(A, B):
    A1, A2 = np.divmod(A, 1 << 16)
    B1, B2 = np.divmod(B, 1 << 16)
    X, Y, Z = np.dot(A1, B1), np.dot(A2, B2), np.dot(A1 + A2, B1 + B2)
    C = (X % MOD) << 32
    C += ((Z - X - Y) % MOD) << 16
    C += Y
    return C % MOD


def power(A, n):
    if n == 1:
        return A
    B = power(A, n // 2)
    B = mult(B, B)
    return mult(A, B) if n & 1 else B


M = power(mat, C)
answer = (M[:, 0].sum() - M.diagonal().sum()) % MOD
print(answer)