n=int(input()) a=list(map(int,input().split())) M=10**9+7 N=n fa=[1] for i in range(1,N+1): fa+=[fa[-1]*i%M] fb=[pow(fa[N],M-2,M)] for i in reversed(range(1,N+1)): fb+=[fb[-1]*i%M] fb.reverse() fc=lambda n,k:fa[n]*fb[k]*fb[n-k]%M if n>=k>=0 else 0 print(sum(a[i]*fc(n-1,i) for i in range(n))%M)