criyle/codenet-compile-errors huggingface dataset:
Language: C

#include<bits/stdc++.h>

#define rep(i,n) for(int i = 0;i < n;++i)
#define rep2(i,n,m) for(int i = n;i < m;++i)
#define all(v) v.begin(),v.end()

using namespace std;
using ll = long long;


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n,l;
    const double PI=3.14159265358979323846;
    cin >> n;
    l = 2*n*PI;
    cout << fixed << setprecision(8);
    cout << l << endl;


}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
#include <math.h>
using namespace std;
#define rep(i,n) for (int i=0;i<(n);i++)
typedef long long ll;
bool aaa[11111111];
const int dx[4]={1,0,-1,0};
const int dy[4]={0,1,0,-1};
ll gcd(ll a, ll b) {
  if(a < b) return gcd(b, a);
  unsigned r;
  while ((r=a%b)) {
    a = b;
    b = r;
  }
  return b;
}
 
 
int main() {
  ll a;
  float x1,x2,bx,b=50000.0001,c=5;
  double xx1,xx2,bx,aa,cc;
  aa=3.1415926535;
  cin>>xx1;
  cout<<fixed<<xx1*aa;
  //vector<vector<bool>> sinsetsu(15,vector<bool>(14)),usotsuki(15,vector<bool>(14));
  //vector<vector<int>> sss(15,vector<int>(14))
  //vector<vector<int>> sss(h,vector<int>(w));
  //vector<int> a(k),b(k);
  //char x;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
int main()
{
    double a,P=6.28318530717958623200;
    cin>>a;
    cout<<P*a<<endl;
}


Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <ios>
#include <iomanip>
#include <algorithm>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <typeinfo>
#include <tuple>
using namespace std;

#define MOD 1000000007
#define INF 1e9+7
#define INF_LONG 1e18
#define rep(i, n) for(int i=0; i<n; ++i)
#define rep1(i, n) for(int i=1; i<=n; ++i)
#define rrep(i, m, n) for(int i=m; i<n; ++i)
#define countof(array) (sizeof(array) / sizeof(array[0]))
typedef long long ll;

#define MAX_N 200000
#define MAX_M 100000
#define MAX_V 100
#define MAX_E 100
#define MAX_Q 100000

int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};

int ddx[] = {-1, 0, 1, 0, -1, 1, -1, 1};
int ddy[] = {0, -1, 0, 1, 1, 1, -1, -1};

string as = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string ab = {"abcdefghijklmnopqrstuvwxyz"};

ll gcd(ll x, ll y) {
  if(y==0) return x;
  else return gcd(y, x%y);
}

ll lcm(ll x, ll y) {
  return (x*y)/gcd(x, y);
}

void yes() {
  cout << "Yes" << endl;
}

void no() {
  cout << "No" << endl;
}

void print_array(int array[], int len) {

  for(int i=0; i<len; ++i) {
    cout << array[i] << endl;
  }

}

ll absolute(ll x) {
  return (x<0)? (-1)*x : x;
}

//g++ AtCoder.cpp -o AtCoder
//AtCoder

//--------------------------

const double PI=3.141592653589;

int main() {

  double r;
  cin >> r;

  cout << 2*r*PI << endl;

  return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
using namespace std;
int main()
{
double r,pi=3.14159265358979323846;
cin>>r;
r*=pi;
cout<<r*2<<endl;
}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <map>
#include <vector>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <climits>
#include <stack>
#include <queue>
#include <set>
#include <cctype>
#include <bitset>
#include <type_traits>

#include <list>
using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define YES(j) cout << (j ? "YES" : "NO") << endl;
#define Yes(j) std::cout << (j ? "Yes" : "No") << endl;
#define yes(j) std::cout << (j ? "yes" : "no") << endl;

int main(void)
{
    double r;
    cin >> r;
    double ans = r * 2 * M_PI;
    printf("%.16f\n", ans);
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>

using namespace std;

int main()
{
	double r;
	cin>>r;
	r *= 2;
	r *= 3.141592; 
	printf("%.10lf\n",r);
	return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <math.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < n; i++)
int main(void){
    double R;
    cin >> R;
    cout << 2 * 3.14159265359 * R << endl;
    return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;

int main() {
  int r=0;
  cin>>r;
  cout<<r*3.1415926535;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
 
int ctoi(const char c){
  switch(c){
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    default : return -1;
  }
}

#define INF 1e+9




int main(){

ios::sync_with_stdio(false);
cin.tie(0);

double n;
cin>>n;
cout << fixed << setprecision(15) <<(n*2)*M_PI << endl;

}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;

#define ll long long

int main() {
    int r;
    cin >> r;

    cout << 2*M_PI*r;
    return 0;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C++

#include "ABC163/ABC163/bits/stdc++.h"

using namespace std;

int main() {
	float in, out;

	cin >> in;
	out = in * in * 3.141592;
	cout << out;

	return 0;
}

Compiler output:
a.cc:1:10: fatal error: ABC163/ABC163/bits/stdc++.h: No such file or directory
    1 | #include "ABC163/ABC163/bits/stdc++.h"
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
Language: C

r=int(input())
import numpy as np
x=2*np.pi*r
print(x)

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | r=int(input())
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'r' [-Wimplicit-int]
main.c:1:3: error: expected expression before 'int'
    1 | r=int(input())
      |   ^~~
Language: C++

#include<iostream>

int main(){
  int r;
  cin >> r;
  cout << 2*3.14159*r << endl;
  
  return0
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin >> r;
      |   ^~~
      |   std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |   cout << 2*3.14159*r << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:6:26: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    6 |   cout << 2*3.14159*r << endl;
      |                          ^~~~
      |                          std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:8:3: error: 'return0' was not declared in this scope
    8 |   return0
      |   ^~~~~~~
Language: C

#include <bits/stdc++.h>
using namespace std;

int main(){
    int r;
    cin >> r;
    const double pi = 3.14159265358979323846;
    cout << 2*r*pi << endl;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include<iomanip>
#include<cmath>
using namespace std;
int main(){
	int N;
	cin>>N;
	cout<<std::setprecision(15)<<2*N*acos(-1);
	return 0;
}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
int main(){
	ios::sync_with_stdio(false);
    cin.tie(NULL);

    double pi = 3.14159265359;
    double r;
    cin >> r;

    cout<< 2*pi*r << "\n";

  return 0;

}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

using System;

namespace A
{
    class Program
    {
        static void Main(string[] args)
        {
            int r = int.Parse(Console.ReadLine());
            Console.WriteLine(r * 2 * 3.141);
        }
    }
}


Compiler output:
main.c:1:1: error: unknown type name 'using'
    1 | using System;
      | ^~~~~
main.c:3:1: error: unknown type name 'namespace'
    3 | namespace A
      | ^~~~~~~~~
main.c:4:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
    4 | {
      | ^
Language: Java

import java.util.*;

public class Sample {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int R = sc.nextInt();
//        int b = sc.nextInt();
//        String s = sc.next();
//        if ((a * b) % 2 == 0)
//            System.out.println("Even");
//        else
//            System.out.println("Odd");
        System.out.println(2 * Math.PI * R);
        
	}
}

Compiler output:
Main.java:3: error: class Sample is public, should be declared in a file named Sample.java
public class Sample {
       ^
1 error
Language: C

#include <stdio>

const double PI=3.14159265358979323846;

int main() {
  double r;
  std::cin >> r;
  std::cout << r * PI *2.0 << std::endl;
}

Compiler output:
main.c:1:10: fatal error: stdio: No such file or directory
    1 | #include <stdio>
      |          ^~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include <bits/stdc++.h>
#include<string>
#include<algorithm>
#include<utility>
using namespace std;


int main(){
    double R;
    double PI=3.1415926535;
    cin >> R;
    cout << 2*R*PI << endl;
    return 0;


}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>
#include <iostream>
#include <vector>
#include <queue>
#include <unordered_map>
#include <random>
#include <stack>
#include <set>
#include <unordered_set>

#define bug(x) cout<<"zdongdebug1: "<<x<<endl;
#define bug2(x, y) cout<<"zdongdebug2: "<<x<<" "<<y<<endl;
#define bug3(x, y, z) cout<<"zdongdebug3: "<<x<<" "<<y<<" "<<z<<endl;
using namespace std;
typedef long long ll;
const int maxn = 100005;
const int mod = 1000000007;


int main() {
#ifdef suiyuan2009
  freopen("/Users/suiyuan2009/CLionProjects/icpc/input.txt", "r", stdin);
  //freopen("/Users/suiyuan2009/CLionProjects/icpc/output.txt", "w", stdout);
#endif
  double  r;
  cin>>r;
  double ret = 2 * acos(-1) * r;
  printf("%.10f\n", ret);
  return 0;
}

Compiler output:
main.c:1:10: fatal error: cstring: No such file or directory
    1 | #include <cstring>
      |          ^~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;

int main() {
  double r;
  cin >> r;
  cout << r*2*3.141592 << endl;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <string>
#include <cstring>
#include <algorithm>
#include <functional>
#include <cmath>
#include <set>
#include <queue>
#include <deque>
#include <vector>
#include <climits>
#include <sstream>
#include <iomanip>
#include <map>
#include <stack>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;

int main()
{
	int R;
	cin >> R;

	const double PI = 3.14159265358979323846;
	cout << fixed << setprecision(5) << R * 2 * PI << endl;

	return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
#define what_is(x) cerr<<#x <<" is "<<x<<endl;
#define ll long long 
#define gcd(a,b) __gcd(a,b)
#define pi 2*acos(0.0)
//use emplace_back() instead of push_back()
template<typename T>
void print(T t)
{
	for(const auto& e:t)cout<<e<<" ";
	cout<<endl;
}
int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	ll t,n,k,r;
	cin>>r;
	cout<<(double)2*3.14159265358*r<<"\n";
	return 0;
}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ll long long
int main(){
    double a;
    cin >> a;
    cout << fixed << setprecision(6)<< a*2*3.141592653589 << endl;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;

int main(){
	double pi = 3.141;
	int n;
	cin >> n;

	cout << 2 * pi*n << endl;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;

int main()
{
    int R;
    cin >> R;
    
    const double PI=3.141592653589;

    double ans = 2*PI*R;

    cout << ans << endl;

}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n)  for (int i = 0; i <  (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)

int main() {
  double Ans = 0;  // 回答：
  int R; cin >> R;  // 半径

  cout << Ans << setprecision(7);	// 計算前に桁数指定
  Ans = R * 2 * 3.141592653589;

  cout << Ans << endl;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
#define fo(i,a,b) for((i)=(a);i<=(b);i++)
#define rfo(i,a,b) for((i)=(a);i>=(b);i--)
#define inrange(x,y,z) (((x)>=(y))&&((x)<=(z)))
#define ALL(vec) ((vec).begin(),(vec).end())
#define SOR(vec) sort(ALL(vec))
#define UNI(vec) (vec).erase(unique(ALL(vec)),(vec).end())
using namespace std;
long double r,pi;
int main(){
	#ifdef FILIN
		#ifndef LOCAL
			freopen(FILIN,"r",stdin);
			freopen(FILOUT,"w",stdout);
		#endif
	#endif
	ios::sync_with_stdio(0);
	cin.tie(NULL);
	cout.tie(NULL);
	cin>>r;r*=2;
	pi=3.1415926535897932384626433832795;
	cout<<fixed<<setprecision(90)<<r*pi<<endl;
	return 0;
}


Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
#define rep(i,a) for(int i=0;i<a;i++)
using namespace std;
using ll = long long;
int main(void){
    int r;
    cin>>r;
    cout<<2*r*3.1415<<endl;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,n) for(int i=1;i<=n;i++)
typedef long long ll;

int main(){
	double r;
	cin >> r;
	double ans = 2*M_PI*r;
	printf("%.10f",ans);
    return 0;
}



Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

r= input()

ans = int(r)*6.28

print(ans)

  

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | r= input()
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'r' [-Wimplicit-int]
main.c:1:4: error: implicit declaration of function 'input' [-Wimplicit-function-declaration]
    1 | r= input()
      |    ^~~~~
main.c:1:4: error: initializer element is not constant
main.c:3:1: error: expected ',' or ';' before 'ans'
    3 | ans = int(r)*6.28
      | ^~~
Language: C

#include <bits/stdc++.h>
using namespace std;

int main() {
  int x ;
  double PI=3.141592653589 ;
  cin >> x ;
  cout << 2 * x * PI <<endl; 
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
double ans;
int n;
int main()
{
	cin>>n;
	ans=(double)n;
	ans*=3.1415;
	ans*=2.0;
	printf("%.3f",ans);
	return 0;
}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>

using namespace std;

double r, ans;

int main()
{
    cin >> r;

    ans = 2 * r * M_PI;

    cout << ans << endl;

    return 0;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>

#include <iomanip>

using std::cin;
using std::cout;
using std::endl;

static double const PI = 3.141592;

int
main()
{
  int R;
  cin >> R;
  cout << std::fixed << PI * (R * 2) << endl;
  return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

//aea ctmr
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
//v.erase(unique(v.begin(),v.end()),v.end());
#define f(i,a,b) for( ll i = a; i < b ; i++ ) 
#define af(i,a,b) for( ll i = a; i >= b ; i--)
#define rep(i,a,b,k) for(ll i = a; i < b ; i+= k )
#define arep(i,a,b,k) for( ll i = a; i >= b ; i-= k)
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define sor(a) sort( a.begin(), a.end() )
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL)
 
using namespace std;
 
typedef long double ld;
typedef long long ll;
typedef  pair <ll, ll> pii;
 
const ll N = 200500;
const ll mod = 1e9 + 7;
const ld PI = acos(-1); 
 
#define TRACE
#ifdef TRACE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << endl;}
 
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << arg1<<" | ";
  __f(comma+1, args...);}
#else
#define trace(...)
#endif
 


int main() {
	fastio;

	ld n;
	cin >> n;

	cout << (ld)2.0 * n * PI << endl;
	
	return 0;
}


Compiler output:
main.c:4:10: fatal error: bits/stdc++.h: No such file or directory
    4 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<stack>
#include<queue>
#include<map>
#include<functional>
#include<math.h>

#define rep(i,n) for(ll i=0;i<(n);i++)
typedef long long ll;
using namespace std;

ll gcd(ll a, ll b) {
	if (b == 0)return a;

	return gcd(b, a%b);
}
ll lcm(ll a, ll b) {
	return a * b / gcd(a, b);
}

int main() {
	int r;
	cin >> r;

	double ans = r * 2 * 3.14;
	printf("%.10f\n", ans);

	return 0;
}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C++

int main(){
    int N,ans;
    cin >> N;
    
    
    
    cout << N*2*3.14159;
    cout << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:3:5: error: 'cin' was not declared in this scope
    3 |     cin >> N;
      |     ^~~
a.cc:7:5: error: 'cout' was not declared in this scope
    7 |     cout << N*2*3.14159;
      |     ^~~~
a.cc:8:13: error: 'endl' was not declared in this scope
    8 |     cout << endl;
      |             ^~~~
Language: C

import numpy as np
N = int(input())
print(2*np.pi*N)

Compiler output:
main.c:1:1: error: unknown type name 'import'
    1 | import numpy as np
      | ^~~~~~
main.c:1:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'as'
    1 | import numpy as np
      |              ^~
main.c:1:14: error: unknown type name 'as'
Language: C

#include <cstdio>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <iterator>
#include <cassert>
#include <numeric>
#pragma warning(disable:4996) 
 
typedef long long ll;
#define MIN(a, b) ((a)>(b)? (b): (a))
#define MAX(a, b) ((a)<(b)? (b): (a))
#define LINF  9223300000000000000
#define LINF2 1223300000000000000
#define INF 2140000000
const long long MOD = 1000000007;
//const long long MOD = 998244353;

using namespace std;


void solve()
{
    int r;
    scanf("%d", &r);
    double ans = (double)r * 2 * 3.141592653589;
    printf("%.10lf\n", ans);

    return;
}

int main(int argc, char* argv[])
{
#if 1
    solve();
#else
    int T;
    scanf("%d", &T);
    int t;
    for(t=0; t<T; t++) {
        printf("Case #%d: ", t+1);
        solve();
    }
#endif
    return 0;
}



Compiler output:
main.c:1:10: fatal error: cstdio: No such file or directory
    1 | #include <cstdio>
      |          ^~~~~~~~
compilation terminated.
Language: C

#include <stdio.h>
#difine PI 3.141592654

int main(void){
  int R;
  scanf("%d", &R);
  printf ("%f", PI * R);
  return 0;
}

Compiler output:
main.c:2:2: error: invalid preprocessing directive #difine; did you mean #define?
    2 | #difine PI 3.141592654
      |  ^~~~~~
      |  define
main.c: In function 'main':
main.c:7:17: error: 'PI' undeclared (first use in this function)
    7 |   printf ("%f", PI * R);
      |                 ^~
main.c:7:17: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

#include <iostream>
using namespace std;
int main()
{
	int r;
	cin >> r;
    cout << r*2*3.14;



Compiler output:
a.cc: In function 'int main()':
a.cc:7:22: error: expected '}' at end of input
    7 |     cout << r*2*3.14;
      |                      ^
a.cc:4:1: note: to match this '{'
    4 | {
      | ^
Language: C

#include <bits/stdc++.h>
using namespace std;

int main(){
  double r;
  cin >> r;
  cout << r*3.141592 << endl;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for (int i=0;i<(n);++i)
using namespace std;
using ll = long long;

int main() {
  int r;
  ll p;

  cin >> n >> m;
  cout << fixed << setprecision(10);
  cout << 2*r*3.14159265358979 << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:10: error: 'n' was not declared in this scope
   10 |   cin >> n >> m;
      |          ^
a.cc:10:15: error: 'm' was not declared in this scope
   10 |   cin >> n >> m;
      |               ^
Language: C

#include <bits/stdc++.h>
using namespace std;
 int main(){
      double a;cin>>a;
      const double PI=acos(-1);
      cout<<fixed<<setprecision(10)<<2*a*PI<<endl;
    }
        






Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include "bits/stdc++.h"
using namespace std;

const int N=2e5;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    double r; cin>>r;
    cout<<fixed<<setprecision(6)<<2*3.14159*r<<endl;
    return 0;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include "bits/stdc++.h"
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>

using namespace std;

int MAX_N = 100;

int main()
{
    long double pi = 3.14159265358979323;
    long double a,b,c;

    cin >> a;

    cout << 2*a*pi << endl;

    return 0;
}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
/*	#include <boost/math/common_factor.hpp>  boost::math::lcm(10,20) ---> use it to find lcm.*/
using namespace std;
#define IO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
typedef long long ll;
// #define int long long 
#define PI pair<int , int >
#define mpr make_pair
#define ff first
#define ss second
#define endl "\n"
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define FO(i,a,b) for(int i = (int)a;i < (int)b;++i)
#define FE(i,a,b) for(int i = (int)a;i <= (int)b;++i)
const int MOD = 1e9+7;
const int MAXN = 1e5+3;
const int inf = 2e9;
int max(int a,int b){	if(a > b)return a; else return b; }
int min(int a, int b){	if(a < b)return a; else return b; }
int dx[] = {1,-1,0,0};
int dy[] = {0,0,-1,1};
bool cmp(PI p1,PI p2){
	if(p1.ff < p2.ff)return true;	// You should not be writing p1.ss <= p2.ss !!!
	else if(p1.ff == p2.ff){ if(p1.ss < p2.ss)return true; return false; }
	return false;
}
/*		1. Take all the inputs
		4. Whenever you do multiplication and division in the same line, beware.
*/
void solve(){
	// int main  or  int32_t main ...
	double n;
	cin >> n;
	double tpi = 6.28318530717958623200;
	cout << tpi*n << endl;
}
/*	memset() can be used to set all values as 0 or -1 for integer data types.*/

int main(){
	IO;
	#ifndef ONLINE_JUDGE
	//freopen("input.txt", "r", stdin);
	#endif // ONLINE_JUDGE
	std::cout << std::setprecision(20); std::cout << std::fixed;
	int t; t = 1;
	// cin >> t;
	while(t--){ solve(); }
	return 0;
}


Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

import sys
input = sys.stdin.readline
import math

def main():
    R = int(input())
    print(2 * math.pi * R)


if __name__ == "__main__":
    main()

Compiler output:
main.c:1:1: error: unknown type name 'import'
    1 | import sys
      | ^~~~~~
main.c:2:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'input'
    2 | input = sys.stdin.readline
      | ^~~~~
Language: C

#include <bits/stdc++.h>
using namespace std;

int main()
{
	double R;
	cin >> R;

	double ans = R * 2 * M_PI;

	cout << fixed << setprecision(12) << ans << endl;
}


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <ios>
#include <iomanip>
#include <algorithm>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <typeinfo>
#include <tuple>
using namespace std;

#define MOD 1000000007
#define INF 1e9+7
#define INF_LONG 1e18
#define rep(i, n) for(int i=0; i<n; ++i)
#define rep1(i, n) for(int i=1; i<=n; ++i)
#define rrep(i, m, n) for(int i=m; i<n; ++i)
#define countof(array) (sizeof(array) / sizeof(array[0]))
typedef long long ll;

#define MAX_N 200000
#define MAX_M 100000
#define MAX_V 100
#define MAX_E 100
#define MAX_Q 100000

int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};

int ddx[] = {-1, 0, 1, 0, -1, 1, -1, 1};
int ddy[] = {0, -1, 0, 1, 1, 1, -1, -1};

string as = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string ab = {"abcdefghijklmnopqrstuvwxyz"};

ll gcd(ll x, ll y) {
  if(y==0) return x;
  else return gcd(y, x%y);
}

ll lcm(ll x, ll y) {
  return (x*y)/gcd(x, y);
}

void yes() {
  cout << "Yes" << endl;
}

void no() {
  cout << "No" << endl;
}

void print_array(int array[], int len) {

  for(int i=0; i<len; ++i) {
    cout << array[i] << endl;
  }

}

ll absolute(ll x) {
  return (x<0)? (-1)*x : x;
}

//g++ AtCoder.cpp -o AtCoder
//AtCoder

//--------------------------



int main() {



  return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include<math.h>
#include<stdlib.h>
#include<string>
#include<limits.h>
#include<utility>
#include<bits/stdc++.h>
#include<vector>
#include<tuple>
#include<algorithm>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
#define rep(i,n) for(int i=0;i<n;i++)
#define ALL(A) A.begin(),A.end()
bool comparator(P a, P b) {
	return a.first / a.second < b.first / b.second;
}

int main() {
	double n;
	cin >> n;
	cout << 2 * M_PI * n << endl;
}


Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>

int main() {
    double pi = 3.141592;

    double R;
    std::cin >> R;

    std::cout << 2 * R * pi << "\n";
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <algorithm>
#include <stdio.h>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <queue>
#include <math.h>
#include <string> 
#include <bits/stdc++.h>
using namespace std;

int main(){
    double r;
    cin >> r;
    cout << r*2*3.141592 << endl;
}

Compiler output:
main.c:1:10: fatal error: algorithm: No such file or directory
    1 | #include <algorithm>
      |          ^~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h> 
using namespace std;
//#define int long long
#include<algorithm>
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<vi> vvi;
#define F first
#define S second
#define pb push_back
#define mk make_pair
#define M 1000000007
#define watch(x) cout << (#x) << " is " << (x) << endl
#define IOS ios_base::sync_with_stdio(false);cin.tie(NULL);
#define rep(i,a,b) for(int i = a; i<= b; i++)
#define all(c) c.begin(), c.end()
#define ws " "
#define ln "\n"
#define get(x) int x; cin >> x;
#define prt printf("hello world\n")
#define MOD 1e16 + 7;

main()
{   
    IOS;
    /*#ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif*/
        float rad;
        cin >> rad;
        float twopi = atan(1)*8;
        cout << twopi*rad << ln;
       return 0;
}


Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
#define ll long long

using namespace std;

int main()
{

float pie = 6.28318530717958623200;
int r;
cin>>r;
cout<<pie*r;

}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <string>
#include <cmath>
#include <set>
#include <bitset>
#include <limits>

using namespace std;

#define ll long long

int main(void){
    double r;
    cin >> r;

    printf("%.9lf", 2*M_PI*r);

    return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
#define ll signed long long int
#define FAST ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define MAXX 1000005
using namespace std;

ll a[MAXX], b[MAXX], c[MAXX], k = 0;

signed main()
{
	FAST;
	ll n, m, f = 0;
	double pi = 3.14;
	cin >> n;
	cout << 2 * pi * n;
	
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MOD 1000000007
#define INF 1LL<<30
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define all(x) (x).begin(),(x).end()

int main(){
    double r;
    cin>>r;
    double ans=2*r*acos(-1);

    cout<<setprecision(10)<<ans<<endl;
}


Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: Java

import java.util.*;

public class atcoder_162_2 {

  static Scanner scan = new Scanner(System.in);

  public static void main(String[] args) {
    int n = scan.nextInt();
    int m = scan.nextInt();

    for (int i = 0; i < m; i++) {
      int d = scan.nextInt();
      n -= d;
    }

    System.out.println(n >= 0 ? n : -1);
  }
}

Compiler output:
Main.java:3: error: class atcoder_162_2 is public, should be declared in a file named atcoder_162_2.java
public class atcoder_162_2 {
       ^
1 error
Language: C

#include<iostream>
#include<algorithm>
#include<functional>
#include<cmath>
#include<string>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<deque>
using namespace std;
#define ll long long
const int mod = 1000000007;
const ll INF = 1000000000000000000;


int main()
{
	int R;
	cin >> R;
	double p = 3.1415926535;
	cout << 2.0 * R * p << endl;
}


Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

import java.util.*;
public class Main{
    public static void main(String [] args){
        Scanner sc = new Scanner(System.in);
        int r = sc.nextInt();
        //int b = sc.nextInt();
        //int c = sc.nextInt();
        //String s = sc.next();

/*        if(N%2 != 0){
        for(int i = 1; i <= N; i++){
            for(int j = i; j <= N; j++){
                c = i*j;
                if(c == N){
                    d = i+j-2;
                    if(min == 0 || min > d) min = d;
            }
        }
    }
}*/
double R = (double)r * Math.PI * 2;
    System.out.println(R);

    }
}

Compiler output:
main.c:1:1: error: unknown type name 'import'
    1 | import java.util.*;
      | ^~~~~~
main.c:1:12: error: expected '=', ',', ';', 'asm' or '__attribute__' before '.' token
    1 | import java.util.*;
      |            ^
main.c:2:1: error: unknown type name 'public'
    2 | public class Main{
      | ^~~~~~
main.c:2:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'Main'
    2 | public class Main{
      |              ^~~~
Language: C

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define INF             1e14
#define dd              double
#define MOD             1000000007
#define my_sizeof(type) ((char *)(&type+1)-(char*)(&type)) 
#define nl              cout<<endl
#define fill(a,val)     memset(a,val,sizeof(a))
#define mp              make_pair
#define endl            "\n"
#define pb              push_back
#define ff              first    
#define ss              second
#define SIZE            200005
#define all(v)          v.begin(),v.end()
#define s(ar,n)         sort(ar,ar+n)
#define rs(ar,n)        sort(ar, ar+n, greater<ll>()) 
#define oa(a,n)         for(ll i=0;i<n;i++)cout<<a[i]<<" ";nl
#define cn(a,n)         for(ll i=0;i<n;i++)cin>>a[i];
#define maxa(ar,N)      *max_element(ar,ar+N)
#define mina(ar,N)      *min_element(ar,ar+N)
#define fastio()        ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define printclock      cerr<<"Time : "<<1000*(long double)clock()/(long double)CLOCKS_PER_SEC<<"ms\n";
ll power(ll x, ll y){
    ll res=1;x=x;
    while(y>0){
        if(y&1)
            res = (res*x);
        y = y>>1;
        x = (x*x);
    }
    return res;
}  
ll logtwo(ll n){
    if(n==1)
        return 0;
    return logtwo(n/2)+1;
}
signed main()
{
    fastio();   
    int t=1;
    //cin>>t;
    while(t--)
    {
        ll r;
        cin>>r;
        cout<<fixed<<setprecision(5)<<2*3.1415*r<<endl;
    }
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>

using namespace std;

int main(){
	int r;
	cin >> r;
	double c = r * 2 * 3.14;
	cout << c;
	return 0;
}

Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C++

#include <stdio.h>
#include <stdlib.h>

#include <iostream>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <stdint.h>
#include <string.h>

//#define _USE_MATH_DEFINES
//#include <math.h>

#include <vector>
#include <list>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <queue>
#include <stack>
#include <deque>
#include <string>

#include <algorithm>
#include <functional>
#include <bitset>
#include <functional>
#include <chrono>
#include <random>
#define sqr(x) (x) * (x)

typedef unsigned int u32;
typedef int i32;
typedef unsigned long long int u64;
typedef long long int i64;
typedef uint16_t u16;
typedef int16_t i16;
typedef uint8_t u8;
typedef int8_t i8;

using namespace std;
using namespace std::chrono;

//const i64 mod = 1000000007ll;
const i64 smod = 998244353ll;
const i64 inf = 1'000'000'000'000'000'000ll + 7;

const double eps = 1e-8;

i64 n;

int main(int argc, char* argv[]) {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cout.precision(15); cout.setf(ios::fixed);

    cin >> n;
    const double M_PI = 3.14159265358979323846;
    cout << 2 * M_PI * n << endl;

    return 0;
}

Compiler output:
In file included from /usr/include/c++/14/cmath:47,
                 from /usr/include/c++/14/random:40,
                 from a.cc:30:
a.cc: In function 'int main(int, char**)':
a.cc:57:18: error: expected unqualified-id before numeric constant
   57 |     const double M_PI = 3.14159265358979323846;
      |                  ^~~~
Language: C

#include <bits/stdc++.h>
using namespace std;

int main() {
	int r;
	cin >> r;

	cout << 2 * M_PI * r << endl;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<iostream>
#include<math.h>
using namespace std;
int main()
{
    // 整数の入力
    int a;
    cin >> a;
    double ret = 2 * a * M_PI; 
    // 出力
    cout << ret << endl;
    return 0;
}


Compiler output:
main.c:1:9: fatal error: iostream: No such file or directory
    1 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
#include <iostream>
using namespace std;

int main(void){
    int r = 0; 

    scanf("%d", &r);

    printf("%lf\n", r * 2.0 * 3.14);

    return 0;

} 


Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <cmath>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <set>
#include <algorithm>
#include <iomanip>
#include <string.h>

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define ALL(a)  (a).begin(),(a).end()

typedef long long lint;

using namespace std;

int main(){
  double R;
  cin>>R;
  cout<<R*2.0*3.14159265358979<<endl;
  return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

R = int(input())
print(2 * R * 3.14159)



Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | R = int(input())
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'R' [-Wimplicit-int]
main.c:1:5: error: expected expression before 'int'
    1 | R = int(input())
      |     ^~~
Language: C

#include <bits/stdc++.h>
using namespace std;

#define ld			long double
#define int         long long
#define pb          push_back
#define pii         pair<int,int>
#define vi          vector<int>
#define vii         vector<pii>
#define mi          map<int,int>
#define mii         map<pii,int>
#define all(a)      (a).begin(),(a).end()
#define x           first
#define y           second
#define sz(x)       (int)x.size()
#define endl        '\n'
#define MOD         100000000
#define sd(t) 		scanf("%d",&(t))
#define rep(i,a,b)  for(int i=a;i<b;i++)
#define hii 		cout << "hii" << endl
#define okay 		cout << "okay" << endl
#define hey 		cout << "hey" << endl
#define M_PIl       3.141592653589793238462643383279502884L 

template <class T> ostream& operator << (ostream &os, const vector<T> &v) { for (T i : v) os << i << ' '; return os; }
template <class T> ostream& operator << (ostream &os, const set<T> &v) { for (T i : v) os << i << ' '; return os; }
template <class T, class S> ostream& operator << (ostream &os, const pair<T, S> &v) { os << v.first << ' ' << v.second; return os; }
template <class T, class S> ostream& operator << (ostream &os, const unordered_map<T, S> &v) { for (auto i : v) os << '(' << i.first << "=>" << i.second << ')' << ' '; return os; } 
 
 
#ifndef ONLINE_JUDGE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template <class Arg1> void __f(const char* name, Arg1&& arg1) { cerr << name << " : " << arg1 << endl; }
    template <class Arg1, class... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args) {
        const char* sep = strchr(names + 1, ',');
        cerr.write(names, sep - names) << " : " << arg1 << "  ";
        __f(sep + 1, args...);
    }
#else
#define trace(...) 
#pragma GCC optimize ("O3")
#pragma GCC optimiz1e ("unroll-loops")
#pragma GCC target("avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define _CRT_SECURE_NO_WARNINGS
#endif // ifndef ONLINE_JUDGE

void fast()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

clock_t time_p=clock();
void starboy1299()
{
    time_p=clock()-time_p;
    cerr<<"Time Taken : "<<(float)(time_p)/CLOCKS_PER_SEC<<"\n";
}
const int mod = 1e9+7;
const int N = 1e5+5;
int arr[N];

void solve()
{	
	int r;
	cin >> r;
	ld ans = 2*(M_PI)*r;

	cout << fixed << setprecision(16) << ans << endl;
}				

int32_t main(){
	fast();
    int t = 1;
    // cin>> t;
    for(int i=1; i<=t; i++){
    	// cout << "Case #" << i << ": ";
    	solve();
    }
}




Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<iomanip>

using namespace std;

int main()
{
    double r;
    cin >> r;
    cout << 3.141592653589793238*2 * r << endl;

    return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C++

#include <iostream>
#include <string>
#include <math.h>
using namespace std;
int main(){
  int R;
  float p;
 cin >> R;
  p=R*2*3.14
    cout << p <<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:13: error: expected ';' before 'cout'
    9 |   p=R*2*3.14
      |             ^
      |             ;
   10 |     cout << p <<endl;
      |     ~~~~
Language: C

#include <bits/stdc++.h>
using namespace std;
#define PI 3.14159265358979323846
int main() {
  double n; cin >> n;
  cout << n*n*PI << endl;
}



Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
using namespace std;
int main (){
 int R;
  cin >> R;
  cout << R*2*3.141;
}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>
#include <string>
#include <algorithm>
#include <ctime>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cassert>
#include <bitset>
#include <list>
#include <cstdio>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <math.h>
#include <cmath>
#include <tuple>
#include <cassert>
#include <array>
#include <iomanip>

using namespace std;
using ll = long long;
using pii = pair<int, int>;
using ti = tuple<int, int, int>;

#define REP(i,m,n) for(int i=(m); i<(n); i++)
#define RREP(i,n,m) for(int i=(n);i>=(m); i--)
#define pb push_back
#define mp make_pair
#define debug(x) cerr << #x << ": " << x << endl
// #define int long long 

const double eps=1e-14;
const int mod = 1e9 + 7;
const int inf = ((1<<30)-1);
const ll linf = (1LL<<60);
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    double r;
    cin >> r;
    cout << fixed << setprecision(6);
    cout << 2*r*M_PI << endl;
    return 0;
}


Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
//#include "stdc++.h"
#include <stdio.h>
using namespace std;

int main(){
    int n;
    scanf("%d", &n);
    float ans;
    ans = 2 * n * 3.1415926;
    printf("%.2f", ans);

    
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C++

include <bits/stdc++.h>
using namespace std;

int main() {
  
  int R;
  cin >> R;
  
  cout << 2 * R * 3.141592 <<endl;
  return 0;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include <bits/stdc++.h>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:7:3: error: 'cin' was not declared in this scope
    7 |   cin >> R;
      |   ^~~
a.cc:9:3: error: 'cout' was not declared in this scope
    9 |   cout << 2 * R * 3.141592 <<endl;
      |   ^~~~
a.cc:9:30: error: 'endl' was not declared in this scope
    9 |   cout << 2 * R * 3.141592 <<endl;
      |                              ^~~~
Language: C

#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main()
{
    ll r;
    cin>>r;
    printf("%Lf",2*3.14159*(long double)r);
}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.