#!/bin/python3

import sys

def solve(a):
    b = []
    for k in range(0,len(a)):
        for i in range(0,len(a)-k):
            j = i + k
            t = max(a[i:j+1])
            b.append(t)
    return b

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