_ = readline()
a = parse.(Int, split(readline(), ' '))

function maxtx(arr::Array{Int, 1})
    n = length(arr)
    b = Array{Int, 1}()
    for k in 1:n
        for i in 1:n-k+1
            push!(b, maximum(arr[i:i+k-1]))
        end
    end
    return b
end
println(sum(maxtx(maxtx(a))))