题解 | #求解立方根#

	
	

		const input = readline()

const target = input[0] === "-" ? 0 - input : input

function out( num ) {
  const res = input[0] === "-" ? 0 - num : num;
  print( res.toFixed(1) )
}

// 暴力法
// let i = 0
// while( i ** 3 <= target ) {
//   i += 0.01
// }
// out( i )

// 二分法
let min, max, eps = 0.0001

function abs( num ) {
  return num > 0 ? num : 0 - num
}

if( target === 1 ) {
  out( target )
}else if( target > 1 ) {
  min = 1
  max = ( target - 1 ) / 2 + 1
}else {
  min = 0
  max = 1
}

function calc() {
  const current = ( min + max ) / 2

  if( abs( current ** 3 - target ) <= eps ) {
    out( current )
    return
  }

  if( current ** 3 > target ) {
    max = current
  }else {
    min = current
  }

  calc()
}

calc()