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A. Flipping Game

time limit per test

1 secondmemory limit per test

256 megabytesinput

standard inputoutput

standard outputIahub got bored, so he invented a game to be played on paper.

He writes *n* integers *a*_{1}, *a*_{2}, ..., *a*_{n}. Each of those integers can be either 0 or 1. He's allowed to do exactly one move: he chooses two indices *i* and *j* (1 ≤ *i* ≤ *j* ≤ *n*) and flips all values *a*_{k} for which their positions are in range [*i*, *j*] (that is *i* ≤ *k* ≤ *j*). Flip the value of *x* means to apply operation *x* = 1 - *x*.

The goal of the game is that after exactly one move to obtain the maximum number of ones. Write a program to solve the little game of Iahub.

Input

The first line of the input contains an integer *n* (1 ≤ *n* ≤ 100). In the second line of the input there are *n* integers: *a*_{1}, *a*_{2}, ..., *a*_{n}. It is guaranteed that each of those *n* values is either 0 or 1.

Output

Print an integer — the maximal number of 1s that can be obtained after exactly one move.

Examples

Input

5

1 0 0 1 0

Output

4

Input

4

1 0 0 1

Output

4

Note

In the first case, flip the segment from 2 to 5 (*i* = 2, *j* = 5). That flip changes the sequence, it becomes: [1 1 1 0 1]. So, it contains four ones. There is no way to make the whole sequence equal to [1 1 1 1 1].

In the second case, flipping only the second and the third element (*i* = 2, *j* = 3) will turn all numbers into 1.

Codeforces (c) Copyright 2010-2020 Mike Mirzayanov

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