时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
64bit IO Format: %lld
空间限制：C/C++/Rust/Pascal 32 M，其他语言64 M
64bit IO Format: %lld
题目描述
Initially, the entire coordinate plane is colored white. N rectangles were painted black. The i-th rectangle has bottom-left corner )
and top-right corner )
for 
. You want to paint some of the black area white so that the remaining black part has a horizontal axis of symmetry. Find the maximum possible area of the remaining black part.
输入描述:
The first line of input contains a single integer N (1 <= N <= 300000), denoting the number of rectangles.
The next N lines of input contain two space-separated integers each, denoting Li, Ri (1 <= Li < Ri <= 109).
输出描述:
Output a single integer, the answer to the problem.