// -*- coding:utf-8-unix -*- #![allow(dead_code)] #![allow(unused_imports)] use std::collections::*; use std::convert::*; use std::convert::{From, Into}; use std::fmt::Debug; use std::fs::File; use std::io::prelude::*; use std::io::*; use std::marker::Copy; use std::mem::*; use std::ops::Bound::*; use std::ops::{Add, Mul, Neg, Sub}; use std::str; use std::vec; use std::{cmp, process::Output}; use std::{cmp::Ordering, env::consts::DLL_PREFIX}; use std::{cmp::Ordering::*, f32::consts::PI}; const INF: i64 = 1223372036854775807; const FINF: f64 = 122337203685.0; const LINF: i64 = 2147483647; const UINF: usize = INF as usize; const MEM_SIZE: usize = 202020; // const MOD: i64 = 1000000007; const MOD: i64 = 998244353; const UMOD: usize = MOD as usize; use std::cmp::*; use std::collections::*; use std::io::stdin; use std::io::stdout; use std::io::Write; // use str::Chars; #[allow(dead_code)] fn read() -> T { let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); s.trim().parse().ok().unwrap() } #[allow(dead_code)] fn readi() -> (i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); iter.next().unwrap().parse::().unwrap() } #[allow(dead_code)] fn read_vec() -> Vec { read::() .split_whitespace() .map(|e| e.parse().ok().unwrap()) .collect() } #[allow(dead_code)] fn read_vec2(n: u32) -> Vec> { (0..n).map(|_| read_vec()).collect() } #[allow(dead_code)] fn readii() -> (i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readff() -> (f64, f64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readiii() -> (i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuu() -> (usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readcc() -> (char, char) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuuu() -> (usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuuuu() -> (usize, usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readiiii() -> (i64, i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readin() -> (i64, i64, i64, i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn grid_01bfs(mat: &Vec>, start: (usize, usize)) -> Vec> { let h = mat.len(); let w = mat[0].len(); let mut res = vec![vec![INF as usize; (w) as usize]; (h) as usize]; let mut q = VecDeque::new(); q.push_back(start); res[start.0][start.1] = 0; while !q.is_empty() { let v = q.pop_front().unwrap(); for i in -1..=1 { for j in -1..=1 { if (i * j as i32).abs() == 1 || (i == 0 && j == 0) { continue; } if v.0 == 0 && i == -1 { continue; } if v.0 == h - 1 && i == 1 { continue; } if v.1 == 0 && j == -1 { continue; } if v.1 == w - 1 && j == 1 { continue; } let nv = ((v.0 as i32 + i) as usize, (v.1 as i32 + j) as usize); let mut d = 1; if mat[nv.0][nv.1] == 1 { d = 1; } else { d = 0; } if (res[nv.0][nv.1] > res[v.0][v.1] + d) { res[nv.0][nv.1] = res[v.0][v.1] + d; if d == 0 { q.push_front(nv); } else { q.push_back(nv); } } } } } return res; } fn solve() { let n: usize = read(); let mut vec: Vec = read_vec(); vec.sort(); vec.reverse(); let mut sum = 0; let mut a = 0; for i in 0..n { sum += vec[i]; if i % 2 == 0 { a += vec[i]; } } if sum < 0 { vec.reverse(); } sum = 0; a = 0; for i in 0..n { sum += vec[i]; if i % 2 == 0 { a += vec[i]; } } if a >= sum { println!("{:?}", sum); } else if a < 0 { println!("{:?}", -1 * sum); } else { println!("{}", 2 * a - sum); } return; } fn main() { solve() }