'use strict'

const main = (INPUT) => {
  const input = INPUT.split('\n')
  const N = input[0]
  const u = input[1].split(' ').map(n => Number(n)).sort((a, b) => a - b)
  while (u.length >= 2) {
    const a = u.shift()
    const b = u.shift()
    const tmp = (a + b) / 2
    u.push(tmp)
    u.sort((a, b) => a - b)
  }
  console.log(u)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))
