import sys

def solve():
    def dfs(i, value):
        if i == n:
            nonlocal ans
            ans = max(ans, value)
            return

        dfs(i + 1, value + a[i])
        dfs(i + 1, value * a[i])
        dfs(i + 1, value - a[i])

    n = int(input())
    a = [int(i) for i in input().split()]
    ans = -(1<<30)

    dfs(1, a[0])

    print(ans)

if __name__ == '__main__':
    solve()