Language: C++

package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
	"strings"

)


func main() {
	solve(os.Stdin, os.Stdout)
}

type ReaderEx struct {
	baseScanner *bufio.Scanner
	words       []string
	nextWordIdx func() int
	initWordIdx func(int)
}

func NewScannerEx(stdin io.Reader) *ReaderEx {
	var this ReaderEx
	var idx int
	var wordsCnt int
	this.baseScanner = bufio.NewScanner(stdin)
	this.baseScanner.Buffer(make([]byte, 0), 1E+11)
	this.nextWordIdx = func() int {
		cur := idx
		idx = (idx + 1) % wordsCnt
		return cur
	}
	this.initWordIdx = func(wc int) {
		idx = 0
		wordsCnt = wc
	}
	return &this
}

func (me *ReaderEx) Scan(doSplit bool) (isScanned bool) {
	isScanned = me.baseScanner.Scan()
	if doSplit {
		me.words = strings.Fields(me.baseScanner.Text())
	} else {
		me.words = []string{me.baseScanner.Text()}
	}
	me.initWordIdx(len(me.words))
	return
}

func (me *ReaderEx) nextBytes() []byte {
	return []byte(me.words[me.nextWordIdx()])
}
func (me *ReaderEx) nextString() string {
	return me.words[me.nextWordIdx()]
}

type StringArray []string

func (me *ReaderEx) nextStringArray() StringArray {
	return me.words[me.nextWordIdx():]
}

func (me StringArray) toStrings() []string {
	return me
}

func (me StringArray) toInts() []int {
	strValues := me.toStrings()
	values := make([]int, len(strValues))
	for i, v := range strValues {
		n, err := strconv.Atoi(v)
		if err != nil {
			panic(err)
		}
		values[i] = n
	}
	return values
}
func (me *ReaderEx) nextInt() int {
	n, err := strconv.Atoi(me.words[me.nextWordIdx()])

	defer func() {
		if err != nil {
			panic(fmt.Sprintf("getInt(%d)", n))
		}
	}()
	return n
}

func pow(x, y, mod int) (ans int) {

	ans = 1
	for bit := 1 << uint(math.Floor(math.Log2(float64(y)))); ; bit >>= 1 {
		if y&bit != 0 {
			ans *= x
			if mod > 0 {
				ans %= mod
			}
		}
		if bit <= 1 {
			return
		}
		ans *= ans
		if mod > 0 {
			ans %= mod
		}
	}
}

type factType struct {
	prime int
	count int
}

func fact(n int) (facts []*factType) {

	for i := 2; i*i <= n; i++ {
		if n%i == 0 {
			fa := factType{prime: i}
			for n%fa.prime == 0 {
				n /= fa.prime
				fa.count++
			}
			facts = append(facts, &fa)
		}
	}
	if n > 1 {
		facts = append(facts, &factType{prime: n, count: 1})
	}
	return facts
}
func dec2bin(n int) (ret []bool) {
	for bit := 1 << uint(math.Floor(math.Log2(float64(n)))); ; bit >>= 1 {
		ret = append(ret, n&bit != 0)

		if bit <= 1 {
			return
		}
	}

}

func abs(v int) int {
	if v < 0 {
		v = -v
	}
	return v
}

func b2i(b bool) (i int) {
	if b {
		i = 1
	} else {
		i = 0
	}
	return
}

func solve(stdin io.Reader, stdout io.Writer) {

	r := NewScannerEx(stdin)
	r.Scan(true)
	rr := r.nextInt()

	fmt.Fprintln(stdout, rr*rr)
}


Compiler output:
a.cc:1:1: error: 'package' does not name a type
    1 | package main
      | ^~~~~~~
a.cc:19:1: error: 'type' does not name a type; did you mean 'typeof'?
   19 | type ReaderEx struct {
      | ^~~~
      | typeof
a.cc:26:1: error: 'func' does not name a type
   26 | func NewScannerEx(stdin io.Reader) *ReaderEx {
      | ^~~~
a.cc:44:6: error: expected constructor, destructor, or type conversion before '(' token
   44 | func (me *ReaderEx) Scan(doSplit bool) (isScanned bool) {
      |      ^
a.cc:55:6: error: expected constructor, destructor, or type conversion before '(' token
   55 | func (me *ReaderEx) nextBytes() []byte {
      |      ^
a.cc:58:6: error: expected constructor, destructor, or type conversion before '(' token
   58 | func (me *ReaderEx) nextString() string {
      |      ^
a.cc:62:1: error: 'type' does not name a type; did you mean 'typeof'?
   62 | type StringArray []string
      | ^~~~
      | typeof
a.cc:68:6: error: expected constructor, destructor, or type conversion before '(' token
   68 | func (me StringArray) toStrings() []string {
      |      ^
a.cc:72:6: error: expected constructor, destructor, or type conversion before '(' token
   72 | func (me StringArray) toInts() []int {
      |      ^
a.cc:84:6: error: expected constructor, destructor, or type conversion before '(' token
   84 | func (me *ReaderEx) nextInt() int {
      |      ^
a.cc:95:1: error: 'func' does not name a type
   95 | func pow(x, y, mod int) (ans int) {
      | ^~~~
a.cc:115:1: error: 'type' does not name a type; did you mean 'typeof'?
  115 | type factType struct {
      | ^~~~
      | typeof
a.cc:120:1: error: 'func' does not name a type
  120 | func fact(n int) (facts []*factType) {
      | ^~~~
a.cc:137:1: error: 'func' does not name a type
  137 | func dec2bin(n int) (ret []bool) {
      | ^~~~
a.cc:148:1: error: 'func' does not name a type
  148 | func abs(v int) int {
      | ^~~~
a.cc:155:1: error: 'func' does not name a type
  155 | func b2i(b bool) (i int) {
      | ^~~~
a.cc:164:1: error: 'func' does not name a type
  164 | func solve(stdin io.Reader, stdout io.Writer) {
      | ^~~~