#!/bin/python

import sys
MOD = 10**9+7

def mox(ll):
    res = []
    for k in xrange(len(ll)):
        for i in xrange(len(ll)-k):
            j = i + k
            res.append(max(ll[i:j+1]))
            
    return res

def solve(A):
    m1 = mox(A)
    return sum(mox(m1))

if __name__ == "__main__":
    n = int(raw_input().strip())
    a = map(int, raw_input().strip().split(' '))
    result = solve(a)
    print result