#!/bin/python3

import sys

def solve(A):
    #  Return the sum of S(S(A)) modulo 10^9+7.
    sa=list(A)
    k=len(A)-1
    i=len(A)-k-1
    j=i+k
    lki=[]
    lk=[]
    for x in range(k):
        sa.append(A[x])
        lk.append(A[x])
        lki.append(A[x])
    for x in range(i+1):
        sa.append(A[x])
        lki.append(A[x])
    ssa=list(sa)    
    x1=0
    '''for x in range(len(lki)):
        ssa.append(lki[x])'''
    for x in range(len(lk)):
        ssa.append(lk[x])
    for x in range(len(sa)):
        x1+=int(sa[x])
    for x in range(x1-1):
        ssa.append(A[0])
    x2=0
    for x in range(len(ssa)):
        x2+=int(ssa[x])
    print(x2)   

if __name__ == "__main__":
    n = int(input().strip())
    A = list(map(int, input().strip().split(' ')))
    result = solve(A)
    '''print(result)'''