#!/bin/python3
import sys

def solve(a,n,b=[],c=[]):
    for k in range(n):
        for i in range(n-k):
            j=i+k
            b.append(max(a[i:j+1]))
    for k in range(len(b)):
        for i in range(len(b)-k):
            j = i + k
            c.append(max(b[i:j + 1]))
    return sum(c)
if __name__ == "__main__":
    n = int(input().strip())
    a = list(map(int, input().strip().split(' ')))
    result=solve(a,n,b=[],c=[])
    print(result)