Problem:
Score : 300 points

Problem Statement

You are given three integers A, B and C. Find the minimum number of operations required to make A, B and C all equal by repeatedly performing the following two kinds of operations in any order:

Choose two among A, B and C, then increase both by 1.

Choose one among A, B and C, then increase it by 2.

It can be proved that we can always make A, B and C all equal by repeatedly performing these operations.

Constraints

0 \leq A,B,C \leq 50

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the minimum number of operations required to make A, B and C all equal.

Sample Input 1

2 5 4

Sample Output 1

2

We can make A, B and C all equal by the following operations:

Increase A and C by 1. Now, A, B, C are 3, 5, 5, respectively.

Increase A by 2. Now, A, B, C are 5, 5, 5, respectively.

Sample Input 2

2 6 3

Sample Output 2

5

Sample Input 3

31 41 5

Sample Output 3

23

Solution in Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func main() {
	fsc := NewFastScanner()
	A := []int{}
	for i := 0; i < 3; i++ {
		A = append(A, fsc.NextInt())
	}
	sort.Ints(A)
	result := 0
	result += A[2] - A[1]
	A[0] += A[2] - A[1]

	diff := A[2] - A[0]
	result += diff / 2
	if diff%2 != 0 {
		result += 2
	}
	fmt.Println(result)
}

//template
type FastScanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func NewFastScanner() *FastScanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1024)
	return &FastScanner{r: rdr}
}
func (s *FastScanner) Next() string {
	s.pre()
	start := s.p
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}
	result := string(s.buf[start:s.p])
	s.p++
	return result
}
func (s *FastScanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *FastScanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}
func (s *FastScanner) NextInt64() int64 {
	v, _ := strconv.ParseInt(s.Next(), 10, 64)
	return v
}

func (s *FastScanner) NextIntArray() []int {
	s.pre()
	start := s.p
	result := []int{}
	for ; s.p < len(s.buf)+1; s.p++ {
		if s.p == len(s.buf) || s.buf[s.p] == ' ' {
			v, _ := strconv.ParseInt(string(s.buf[start:s.p]), 10, 0)
			result = append(result, int(v))
			start = s.p + 1
		}
	}

	return result
}

func (s *FastScanner) NextInt64Array() []int64 {
	s.pre()
	start := s.p
	result := []int64{}
	for ; s.p < len(s.buf)+1; s.p++ {
		if s.p == len(s.buf) || s.buf[s.p] == ' ' {
			v, _ := strconv.ParseInt(string(s.buf[start:s.p]), 10, 64)
			result = append(result, v)
			start = s.p + 1
		}
	}
	return result
}

func (s *FastScanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *FastScanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}

//Max,Min
func IntMax(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func Int64Max(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}
func Float64Max(a, b float64) float64 {
	if a < b {
		return b
	}
	return a
}

func IntMin(a, b int) int {
	if a > b {
		return b
	}
	return a
}

func Int64Min(a, b int64) int64 {
	if a > b {
		return b
	}
	return a
}
func Float64Min(a, b float64) float64 {
	if a > b {
		return b
	}
	return a
}

//Gcd
func IntGcd(a, b int) int {
	if a < b {
		b, a = a, b
	}
	if b == 0 {
		return a
	}
	return IntGcd(b, a%b)
}
func Int64Gcd(a, b int64) int64 {
	if a < b {
		b, a = a, b
	}
	if b == 0 {
		return a
	}
	return Int64Gcd(b, a%b)
}

func IntAbs(a int) int {
	if a < 0 {
		a *= -1
	}
	return a
}

func Int64Abs(a int64) int64 {
	if a < 0 {
		a *= -1
	}
	return a
}