'use strict'
function main(input) {
  input = input.split('\n');
  const length = Number(input[0])
  input = input[1].split(' ')
  let min = 10000000000
  let minusCount = 0
  input = input
    .map(val => {
      val = Number(val)
      let abs = Math.abs(val)
      if (val < 0) minusCount++
      if (abs < min) min = abs
      return abs
    })
    .reduce((prev, current) => prev + current)

  if (minusCount % 2) input -= min * 2
  
  console.log(input, minusCount, length, min)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
