Problem:
Score : 100 points

Problem Statement

We have two integers: A and B.

Print the largest number among A + B, A - B, and A \times B.

Constraints

All values in input are integers.

-100 \leq A,\ B \leq 100

Input

Input is given from Standard Input in the following format:

A B

Output

Print the largest number among A + B, A - B, and A \times B.

Sample Input 1

-13 3

Sample Output 1

-10

The largest number among A + B = -10, A - B = -16, and A \times B = -39 is -10.

Sample Input 2

1 -33

Sample Output 2

34

The largest number among A + B = -32, A - B = 34, and A \times B = -33 is 34.

Sample Input 3

13 3

Sample Output 3

39

The largest number among A + B = 16, A - B = 10, and A \times B = 39 is 39.

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

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	//	"strings"
)

func main() {
	sc := NewScanner()

	a := sc.NextInt()
	b := sc.NextInt()

	x := a + b
	y := a - b
	z := a * b

	ans := 0
	if x > y {
		ans = x
	} else {
		ans = y
	}
	if ans < z {
		ans = z
	}
	fmt.Printf("%v\n", ans)
}

type Scanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func NewScanner() *Scanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1000)
	return &Scanner{r: rdr}
}
func (s *Scanner) 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 *Scanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *Scanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}

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

	return result
}

func (s *Scanner) NextMap() map[int]bool {
	s.pre()
	start := s.p
	mp := map[int]bool{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			mp[v] = true
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	mp[v] = true

	return mp
}

func (s *Scanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *Scanner) 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
		}
	}
}