n = int(input()) a = list(map(int,input().split(' '))) i = 0 while i < n and a[i] == 0: i += 1 if i == n: print(0) exit(0) ans = abs(a[i]) i += 1 sign = 0 for x in a[i:]: sign ^= x < 0 if sign == 0: for x in a[i:]: if x in [0,1]: ans += x else: ans *= x else: mx = -10 ** 9 for x in a[i:]: if x < 0: mx = max(mx,x) for x in a[i:]: if x in [0,1]: ans += x elif x == mx: ans -= x mx = 0 else: ans *= x print(ans)