n=int(input())
a=list(map(int,input().split()))
b=[]
for k in range(n):
    for i in range(n-k):
        j=i+k
        if j<n:
            b.append(max(a[i:j+1]))
a=b[:]
b=[]
n=len(a)
for k in range(n):
    for i in range(n-k):
        j=i+k
        if j<n:
            b.append(max(a[i:j+1]))
print(sum(b))