Language: C

package main

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

var sc, wr = bufio.NewScanner(os.Stdin), bufio.NewWriter(os.Stdout)

func scanString() string   { sc.Scan(); return sc.Text() }
func scanRunes() []rune    { return []rune(scanString()) }
func scanInt() int         { a, _ := strconv.Atoi(scanString()); return a }
func scanInt64() int64     { a, _ := strconv.ParseInt(scanString(), 10, 64); return a }
func scanFloat64() float64 { a, _ := strconv.ParseFloat(scanString(), 64); return a }

func scanInts(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = scanInt()
	}
	return res
}

func debug(a ...interface{}) { fmt.Fprintln(os.Stderr, a...) }

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}
func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}
func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

//•*¨*•.¸¸♪main•*¨*•.¸¸♪(　-ω-)ノ　(　・ω・)
func main() {
	defer wr.Flush()
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 10000), 1001001)

	r := scanFloat64()
	fmt.Fprintln(wr, 2*r*math.Pi)
}


Compiler output:
main.c:1:1: error: unknown type name 'package'
    1 | package main
      | ^~~~~~~
main.c:3:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'import'
    3 | import (
      | ^~~~~~
main.c:14:1: error: unknown type name 'func'
   14 | func scanRunes() []rune    { return []rune(scanString()) }
      | ^~~~
main.c:14:6: error: 'scanRunes' declared as function returning an array
   14 | func scanRunes() []rune    { return []rune(scanString()) }
      |      ^~~~~~~~~
main.c: In function 'scanRunes':
main.c:14:20: error: expected declaration specifiers before 'rune'
   14 | func scanRunes() []rune    { return []rune(scanString()) }
      |                    ^~~~
main.c:15:1: error: unknown type name 'func'
   15 | func scanInt() int         { a, _ := strconv.Atoi(scanString()); return a }
      | ^~~~
main.c:15:16: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int'
   15 | func scanInt() int         { a, _ := strconv.Atoi(scanString()); return a }
      |                ^~~
main.c:16:1: error: unknown type name 'func'
   16 | func scanInt64() int64     { a, _ := strconv.ParseInt(scanString(), 10, 64); return a }
      | ^~~~
main.c:16:18: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int64'
   16 | func scanInt64() int64     { a, _ := strconv.ParseInt(scanString(), 10, 64); return a }
      |                  ^~~~~
main.c:17:1: error: unknown type name 'func'
   17 | func scanFloat64() float64 { a, _ := strconv.ParseFloat(scanString(), 64); return a }
      | ^~~~
main.c:17:20: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'float64'
   17 | func scanFloat64() float64 { a, _ := strconv.ParseFloat(scanString(), 64); return a }
      |                    ^~~~~~~
main.c:19:1: error: unknown type name 'func'
   19 | func scanInts(n int) []int {
      | ^~~~
main.c:19:15: error: unknown type name 'n'
   19 | func scanInts(n int) []int {
      |               ^
main.c:27:1: error: unknown type name 'func'
   27 | func debug(a ...interface{}) { fmt.Fprintln(os.Stderr, a...) }
      | ^~~~
main.c:27:13: error: expected ')' before '...' token
   27 | func debug(a ...interface{}) { fmt.Fprintln(os.Stderr, a...) }
      |             ^~~~
      |             )
main.c:29:1: error: unknown type name 'func'
   29 | func abs(a int) int {
      | ^~~~
main.c:29:10: error: unknown type name 'a'
   29 | func abs(a int) int {
      |          ^
main.c:35:1: error: unknown type name 'func'
   35 | func min(a, b int) int {
      | ^~~~
main.c:35:14: error: expected ')' before 'int'
   35 | func min(a, b int) int {
      |              ^~~~
      |              )
main.c:41:1: error: unknown type name 'func'
   41 | func max(a, b int) int {
      | ^~~~
main.c:41:14: error: expected ')' before 'int'
   41 | func max(a, b int) int {
      |              ^~~~
      |              )
main.c:49:1: error: unknown type name 'func'
   49 | func main() {
      | ^~~~
main.c:49:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
   49 | func main() {
      |             ^
main.c:57: error: expected '{' at end of input