n = int(input())
A = list(map(int,input().split()))

ans = 0
if [str(i) for i in A].count(str(A[0])) == n:
    ans = A[0]*2**(n-1)
else:
    for i in range(n):
        if i == 0 or i == n-1:
            ans += A[i]
        else:
            ans += A[i]*(n-1)
    
print(ans%(10**9+7))