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

#include <iostream>
#include <string>
#include <iomanip>
#include <math.h>
#define PI acos(-1)
#include <cmath>


using namespace std;

int main(){
	
	
	double R,A;
	cin >> R;
	A=2*R*PI;
	
//	Fahrenheit=Celsius*9/5+32;
//	cout << fixed;
	
	cout << setprecision(20) << A;
	
	return 0;
	
	
	
}

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

/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int r;
    cin>>r;
    
    double pi = 3.14159265358979323846;
    cout<<setprecision(9)<<pi*2*r;
    
}


Compiler output:
main.c:9:10: fatal error: bits/stdc++.h: No such file or directory
    9 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
 
int main() {
  double R;
  cin >>R;
  cout <<R*3.1415926535<<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<stdio.h>

int main()
{
	int a;
	double b;
	scanf("%d", &a);
	b = a * 6.28318530;// 717958623200;
	printf("%f", b);
	return 0;
}

Compiler output:
a.cc:1:1: error: stray '##' in program
    1 | ##include<stdio.h>
      | ^~
a.cc:1:3: error: 'include' does not name a type
    1 | ##include<stdio.h>
      |   ^~~~~~~
Language: Java

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double radius = scan.nextInt();
        double result = 2 * 3.14 * radius;
        
        System.out.println(result);
    }
}

Compiler output:
Main.java:3: error: cannot find symbol
        Scanner scan = new Scanner(System.in);
        ^
  symbol:   class Scanner
  location: class Main
Main.java:3: error: cannot find symbol
        Scanner scan = new Scanner(System.in);
                           ^
  symbol:   class Scanner
  location: class Main
2 errors
Language: C

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

typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll, ll> ii;
typedef vector<ii> vii;
typedef set<ll> si;
typedef map<string, ll> msi;
#define hell 1000000007
#define MAX 1000000000
#define max_int 1000000
#define F first
#define re 15000000
#define S second
#define pb push_back
#define all(a)  (a).begin(),(a).end()
#define rep(i,a,b) for(ll i = a;i<b;i++)
#define pi 3.14159265358979311600
#define r0 return 0

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
 
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    long double n;
    cin>>n;
    cout<<setprecision(20)<<fixed<<2*pi*n;
  
 
    
}
 

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 <>
using namespace std;

int main (){
  int R;
  cin>>R;
  cout<<R*6.2830<<endl;
}


Compiler output:
main.c:1:10: error: empty filename in #include
    1 | #include <>
      |          ^~
main.c:2:1: error: unknown type name 'using'
    2 | using namespace std;
      | ^~~~~
main.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    2 | using namespace std;
      |                 ^~~
main.c: In function 'main':
main.c:6:3: error: 'cin' undeclared (first use in this function)
    6 |   cin>>R;
      |   ^~~
main.c:6:3: note: each undeclared identifier is reported only once for each function it appears in
main.c:7:3: error: 'cout' undeclared (first use in this function)
    7 |   cout<<R*6.2830<<endl;
      |   ^~~~
main.c:7:19: error: 'endl' undeclared (first use in this function)
    7 |   cout<<R*6.2830<<endl;
      |                   ^~~~
Language: C

#include <bits/stdc++.h>
int main(void){
int r;
cin>>r;
r*=M_PI;
cout<<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<stdio.h>
#include<math.h>
const double pi=acos(-1.0);
using namespace std;
int main()
{
	double a;
	scanf("%lf",&a);
	printf("%lf",2*a*pi);
}


Compiler output:
main.c:4:1: error: unknown type name 'using'
    4 | using namespace std;
      | ^~~~~
main.c:4:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    4 | using namespace std;
      |                 ^~~
Language: C++

using namespace std;
using ull = unsigned long long;
using ld = long double;
using lll = boost::multiprecision::cpp_int;
using ll = long long;
#define FOR(i, N) for(ll i = 0; i < N; ++i)
 
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
int main(){
  ll R;
  cin>>R;
  printf("%.5lf\n", R*2*M_PI);
  return 0;
}

Compiler output:
a.cc:4:13: error: 'boost' does not name a type
    4 | using lll = boost::multiprecision::cpp_int;
      |             ^~~~~
a.cc: In function 'int main()':
a.cc:12:3: error: 'cin' was not declared in this scope
   12 |   cin>>R;
      |   ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | using namespace std;
a.cc:13:25: error: 'M_PI' was not declared in this scope
   13 |   printf("%.5lf\n", R*2*M_PI);
      |                         ^~~~
a.cc:13:3: error: 'printf' was not declared in this scope
   13 |   printf("%.5lf\n", R*2*M_PI);
      |   ^~~~~~
a.cc:1:1: note: 'printf' is defined in header '<cstdio>'; this is probably fixable by adding '#include <cstdio>'
  +++ |+#include <cstdio>
    1 | using namespace std;
Language: C++

#include <bits/stdc++.h>

using namespace std;
 
#define PB(x)	push_back(x)
#define ALL(x)	(x).begin(), (x).end()
#define ALLR(x)	(x).rbegin(), (x).rend()
#define MP(x)	make_pair(x)
 
#define debug(_x)		cerr << #_x << '=' << _x << endl;
#define debug2(_x, _y)	cerr << #_x << '=' << _x << ' ' << #_y << '=' << _y << endl;
#define debugn(_a)		cerr << #_a << ": "; for (const auto _x: _a) cerr << _x << ' '; cerr << endl;

#define FAST_IO ios::sync_with_stdio(false); cin.tie(0)

#define int long long int

typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ii> vii;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef unsigned long long ull;

const int INF = LONG_LONG_MAX;
const int NINF = LONG_LONG_MIN/2;

const double PI = 3.14159265358979311;
int32_t main() {
	FAST_IO;
	
	int r;
	cin >> r;
	
	cout << setfixed() << setprecision(9) << PI*2*r << endl;
}

// g++ -Wall -Wextra -Wshadow -fsanitize=undefined


Compiler output:
a.cc: In function 'int32_t main()':
a.cc:36:17: error: 'setfixed' was not declared in this scope; did you mean 'setuid'?
   36 |         cout << setfixed() << setprecision(9) << PI*2*r << endl;
      |                 ^~~~~~~~
      |                 setuid
Language: C

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

int main() {
    float r;
    cin >> r;
    float ans;
    ans = r * 3.1415926 * 2.0;
    printf("%.3f", 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++

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

int main()
{
  double r;
  cin>>r;
  double ans = 2 * 3.14 *r;
  cout<<fixed<<setprecision(10)<<ans;
}

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

#include <iostream>
#include <cstdio>
#define Pi 3.141592635 
using namespace std;
double R;
double C;
int main()
{
	scanf("%lf",&R);
	C=2*R*Pi;
	printf("lf",C);
} 


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

#include <iostream>
#include<vector>
#include<algorithm>
using namespace std;

int main() {
	int a;
	cin >> a;
	cout << a * 2* 3.14159265358979323846264338327950288419716939937510 << 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<stdio.h>

#include<math.h>

int main()

{
    int r,b;

    double c;

    scanf("%d",&r);

    c = 2*r*acos(-1);

    printf("%lf\n",c);

    return 0;



Compiler output:
main.c: In function 'main':
main.c:18:5: error: expected declaration or statement at end of input
   18 |     return 0;
      |     ^~~~~~
Language: C

#include<bits/stdc++.h>
using namespace std;
#define pi 3.1416
int main(){
double r,ans;
scanf("%lf",&r);
ans = 2*pi*r;
printf("%.4f",ans);
}


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>

int main() {
  int n;
cin >> n;
    double pi = 3.141592;
    double ans = n * 2 * pi;

    co(ans);

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:1: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 | cin >> n;
      | ^~~
      | std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 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:9:5: error: 'co' was not declared in this scope; did you mean 'cos'?
    9 |     co(ans);
      |     ^~
      |     cos
Language: C

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

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


void solve(long long N){
  cout << << 2 * N * M_PI << endl;
}

int main(){
    long long N;
    scanf("%lld",&N);
    solve(N);
    return 0;
}

Compiler output:
a.cc: In function 'void solve(long long int)':
a.cc:6:11: error: expected primary-expression before '<<' token
    6 |   cout << << 2 * N * M_PI << endl;
      |           ^~
Language: C++

#include <iostream>
#include <string>
using namespace std;
 
int main() {
    int R;
    cin >> R;
 
    cout << 2*R*3.14159265 << endl;
}
#include <iostream>
#include <string>
using namespace std;

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

    cout << 2*R*3.14159265 << endl;
}

Compiler output:
a.cc:15:5: error: redefinition of 'int main()'
   15 | int main() {
      |     ^~~~
a.cc:5:5: note: 'int main()' previously defined here
    5 | int main() {
      |     ^~~~
Language: Java

package com.atc.abc163;

public class Solution100 {

	public static void main(String[] args) {
		System.out.println(Double.valueOf(args[0]) * 2 * Math.PI);
	}

}


Compiler output:
Main.java:3: error: class Solution100 is public, should be declared in a file named Solution100.java
public class Solution100 {
       ^
1 error
Language: C++

#include <iostream>

using namespace std;

int main () 
{
  int a;
  cin >> a;
  a *= 3.14159; 
  a *= 2;
  cout << b << '\n';
  }


Compiler output:
a.cc: In function 'int main()':
a.cc:11:11: error: 'b' was not declared in this scope
   11 |   cout << b << '\n';
      |           ^
Language: C++

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

 
using ld = long double;
const double PI = 6.28318530717958623200;

int main() {
  int r;cin>>r;
  ld a = r*PI;
  cout<<a
}


Compiler output:
a.cc: In function 'int main()':
a.cc:11:10: error: expected ';' before '}' token
   11 |   cout<<a
      |          ^
      |          ;
   12 | }
      | ~
Language: C

#include <bits/stdc++.h>
using namespace std;
int main() {
  double R;
  cin >> R;
  double E;
  E = R * 2 * 3.141592653589;
  cout << E << 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++

/*Stay true to yourself, yet always be open to learn. Work hard, and never give up on your dreams, 
even when nobody else believes they can come true but you. These are not cliches but real tools you 
need no matter what you do in life to stay focused on your path.
*/
 
 /*Pppppppp    UU      UU     CCCCCCCC    CCCCCCCC     HH     HH     UU      UU
   pp    pp    UU      UU     CC          CC           HH     HH     UU      UU
   pp    pp    UU      UU     CC          CC           HHHHHHHHH     UU      UU
   pppppppp    UU      UU     CC          CC           HHHHHHHHH     UU      UU
   pp          UU      UU     CC          CC           HH     HH     UU      UU
   pp          UUUUUUUUUU     CCCCCCCC    CCCCCCCC     HH     HH     UUUUUUUUUU
   */
 
#include <bits/stdc++.h>
using namespace std;
 
#define int long long
typedef long long ll;
#define loop(i,n)  for(int i=0;i<n;i++)
#define ford(i,a,b) for(int i=b;i>=a;i--)
#define read(a) int a; cin >>a;
#define readarr(a,n) int a[n] ; for(int i=0;i<n;i++) cin >> a[i];
#define readmat(a,n,m) int a[n][m]; for(int i=0;i<n;i++) for(j=0;j<m;j++) cin >> a[i][j];
#define pb push_back
#define ff first
#define ss second
#define vi vector<int>
#define pi pair<int,int>
#define vii vector<vector<int>>
#define sti set<int>
#define vpi vector<pair<int,int>>
#define print(a,n) for(int i=0;i<n;i++) cout<<a[i]<<" "; cout<<endl;
#define printmat(a,n,m) for(int i=0;i<n;i++) {for(j=0;j<m;j++) cout<<a[i][j]<<" "; cout<<endl;}
#define fast ios_base::sync_with_stdio(false);  cin.tie(NULL);
#define endl "\n"
#define mp make_pair
const ll inf = 1e18;
const ll mod = 1e9 + 7;
 
 int gcd(int a,int b){
 	if(b==0) return a;
 	return gcd(b,a%b);
 }
 

signed main()
{
 
    fast;
    double pi = 3.14159265358979323846;
    double r;
    cin >> r;
    double p = 2*pi*r;
    cout<<setprecision(5)<<p<<endl;
    
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:50:15: error: invalid declarator before '=' token
   50 |     double pi = 3.14159265358979323846;
      |               ^
a.cc:53:20: error: expected primary-expression before '*' token
   53 |     double p = 2*pi*r;
      |                    ^
Language: C++

  float L;
  int R;
  cin >> R;
  L = R *2 * 3.14;
  cout << L << endl;

Compiler output:
a.cc:3:3: error: 'cin' does not name a type
    3 |   cin >> R;
      |   ^~~
a.cc:4:3: error: 'L' does not name a type
    4 |   L = R *2 * 3.14;
      |   ^
a.cc:5:3: error: 'cout' does not name a type
    5 |   cout << L << endl;
      |   ^~~~
Language: C++

#include <iostream>
#include <numbers>

using namespace std;
int main(void) {
  double input;
  cin >> input;
  cout << 2*input * pi << endl;
	return 0;
}
  

Compiler output:
a.cc: In function 'int main()':
a.cc:8:21: error: 'pi' was not declared in this scope
    8 |   cout << 2*input * pi << endl;
      |                     ^~
Language: C

#include<stdio.h>

#include<iostream>
#include<stdlib.h>
using namespace std;


int main(){
  double PI=3.14159265358979323846;
  double R;scanf("%lf",&R);

  printf("%lf\n",2*PI*R);

  return 0;
}



Compiler output:
main.c:3:9: fatal error: iostream: No such file or directory
    3 | #include<iostream>
      |         ^~~~~~~~~~
compilation terminated.
Language: C

#include <iostream>

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

    std::cout << 2 * (double)R * 3.141592 << std::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;
  cin >> r;
  double p = r * 3.14159265 * 2;
  cout << fixed << setprecision(8)
  cout << p << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:35: error: expected ';' before 'cout'
    8 |   cout << fixed << setprecision(8)
      |                                   ^
      |                                   ;
    9 |   cout << p << endl;
      |   ~~~~
Language: C

#include<stdio.h>
#include<math.h>

int main()[
double R=0;
double L=0;

scanf("%lf", &R);

L=2*M_PI*R;

printf("%lf", &L);

]

Compiler output:
main.c:5:1: error: expected expression before 'double'
    5 | double R=0;
      | ^~~~~~
Language: C++

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

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

Compiler output:
a.cc: In function 'int main()':
a.cc:9:5: error: 'cin' was not declared in this scope
    9 |     cin>>a;
      |     ^~~
a.cc:2:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
    1 | #include <math.h>
  +++ |+#include <iostream>
    2 | //#include <bits/stdc++.h>
a.cc:11:5: error: 'cout' was not declared in this scope
   11 |     cout<<a<<endl;
      |     ^~~~
a.cc:11:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:11:14: error: 'endl' was not declared in this scope
   11 |     cout<<a<<endl;
      |              ^~~~
a.cc:2:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
    1 | #include <math.h>
  +++ |+#include <ostream>
    2 | //#include <bits/stdc++.h>
Language: C

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

#define ll long long int
#define PI acos(1.0)

#define Bit_off(val,pos)       (val & (~(1<<pos)))
#define Bit_on(val,pos)        (val | (1<<pos))
#define Bit_toggle(val,pos)    (val ^ (1<<pos))
#define Bit_check(val,pos)     (bool)(val & (1<<pos))
#define odd_even(val)          (bool)(val & 1)
#define koita_1_ase(val)       (__builtin_popcount(val))

ll ar[500009],br[500009],cr[500009];
map<ll,ll>mp,mp1;
vector<ll>v;
string s,d;

int main()
{
    ll a,b,c,i,j,k,x,y,z,f,g,h;
    
    double q,w,e,r;
    
    cin>>q;
    
    r=(2.0*q*PI);
    
    cout<<fixed<<setprecision(6)<<r<<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>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main(){
  
  double pi = 3.1415926535;
  int R;
  cin >> R;
  float cir = 2 * pi * R;
  cout << cir << 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

import math

R = int(input())
ensyu = 2 * 3.14 * R
print(ensyu)

Compiler output:
main.c:1:1: error: unknown type name 'import'
    1 | import math
      | ^~~~~~
main.c:3:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'R'
    3 | R = int(input())
      | ^
Language: C++

#include<conio.h>
#include<iostream>
using namespace std;
int main()
{
  long double r,res,n=22,d=7;
  cin>>r;
  res=n/d;
  res=res*2*r;
  cout<<res;
  return 0;
}


Compiler output:
a.cc:1:9: fatal error: conio.h: No such file or directory
    1 | #include<conio.h>
      |         ^~~~~~~~~
compilation terminated.
Language: C

#include <bits/stdc++.h>
using namespace std;
#define fr(i,n) for (int i=0;i<n;i++)
#define rep(i,a,b) for (int i=a;i<=b;i++)
#define per(i,a,b) for (int i=a;i>=b;i--)
#define all(cont) cont.begin(), cont.end()
#define unique(a)  sort(all(a)) , (a).erase(unique((a).begin(), (a).end()),(a).end())
#define rall(cont) cont.rbegin(), cont.rend()
#define sz(x) (int)(x).size()
#define fastio          ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define PB push_back
#define endl "\n"
#define f first
#define s second
#define mset(m,v) memset(m,v,sizeof(m))
#define mod 1000000007
const int N = 2e5 + 5;
#define PI acos(-1.0)
long double EPS = 1e-9;
typedef long long ll;
#define int long long
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pair<int, int>> vpii;
#define pqll_max priority_queue<ll> // max heap. push(),pop(),top(),size(),empty()
#define pqll_min priority_queue<ll,vector<ll>,greater<ll> >
#define lb(v,val)   lower_bound(v.begin(),v.end(),val) //first equal to or lower than [------------
#define ub(v,val)   upper_bound(v.begin(),v.end(),val) //first greater than ------------)
#define bs(v,x) binary_search(v.begin(),v.end(),x)
inline ll add(ll x, ll y) { x += y; if (x >= mod) x -= mod; return x; }
inline ll sub(ll a, ll b) { if (a < b)swap(a, b); return (((a%mod) - (b%mod) + mod) % mod); }
inline ll mul(ll x, ll y) { return (x%mod * 1ll * y%mod) % mod; }
inline ll pwr(ll a, ll b) { ll x = 1 % mod; while (b) { if (b & 1) x = mul(x, a); a = mul(a, a); b >>= 1; }return x % mod; }
inline ll inv(ll a) { return pwr(a, mod - 2) % mod; }
ll gcd(ll a, ll b) { if (!a)return b % mod; return gcd(b%a, a) % mod; }
#define debug(x) cout << #x << " = " << x << endl;
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
	cout << name << " : " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ','); cout.write(names, comma - names) << " : " << arg1 << " | "; __f(comma + 1, args...);
}
#define in(container) for (auto &it : container) cin>>it;
#define out(container) for (auto it : container) cout << it << " "; cout << endl;
void pre() {
}
void solve() {
	int n;
	cin >> n;
	cout << 2 * PI*n << endl;
}
signed main()
{
	fastio;
	cout<<fixed<<setprecision(15);
	//clock_t begin = clock();
	//pre();
	int tc;
	tc = 1;
	//cin >> tc;
	while (tc--) {
		solve();
	}
	//clock_t end = clock();double elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;cerr << elapsed_secs;
}


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<<acos(-1)*2*r;
	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, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int debug = 0;
#define PI 3.14159265359

int main()
{
    int r;
    cin >> r;
    printf("%.20f\n",2*r*PI);
    //     cout << 2 * r * PI << 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 <cmath>
#include <algorithm>
#include <bitset>
#include <iomanip>
#include <cstdio>

using namespace std;

int main() {
	double pai = 3.141592653589793;

	int64_t r;
	cin >> r;

	cout << r * 2 * pai << endl;
	return 0
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:17: error: expected ';' before '}' token
   17 |         return 0
      |                 ^
      |                 ;
   18 | }
      | ~
Language: C

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

#define ll long long int
#define pb push_back
#define fi first
#define se second
#define mp make_pair
#define mt make_tuple
#define all(A) A.begin(), A.end()
#define sz(A) (int)A.size()
typedef vector <int> vi;
typedef vector <ll> vl;
typedef pair <int, int> pii;
const ll mod = 1e9 + 7;
//const ll mod = 998244353;
const int inf = 1e9;
//const ll inf = 1e18;
const int N = 2e5;

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	long double pi = 3.14159265358979323846;
	long double r;
	cin >> r;
	cout << 2 * pi * r << "\n";
 	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: Java

package atcoder;

import java.util.Scanner;

public class main {
	static int R;
	static double L;
	public static void main(String args[]){
		Scanner scanner =new Scanner(System.in);
		R=scanner.nextInt();
		L=R*2*3.14;
		System.out.println(L);
	}
}


Compiler output:
Main.java:5: error: class main is public, should be declared in a file named main.java
public class main {
       ^
1 error
Language: C++

#include <algorithm>
#include <cmath>
#include <queue>
#include <iomanip>
#include <map>
#include <set>
#include <tuple>
#include <unordered_map>
#include <iterator>
#include <string>
#include <limits>
 
using namespace std;
 
using i64 = int64_t;
using P = pair<i64, i64>;
i64 mod = 1000000007;
int int_max = 2147483647;
int max_n = 1e5;
 
 
int main(int argc, char **argv) {
    double r;
    cin >> r;
 
    cout<< setprecision(10) << r*2.* M_PI <<endl;
 
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, char**)':
a.cc:24:5: error: 'cin' was not declared in this scope
   24 |     cin >> r;
      |     ^~~
a.cc:10:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
    9 | #include <iterator>
  +++ |+#include <iostream>
   10 | #include <string>
a.cc:26:5: error: 'cout' was not declared in this scope
   26 |     cout<< setprecision(10) << r*2.* M_PI <<endl;
      |     ^~~~
a.cc:26:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
Language: C

#include<bits/stdc++.h>
using namespace std;
long long n;
int main()
{
    cin>>n;
    cout<<n*2*3.14159265358979323846;
}


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 fi        first
#define se        second
#define pb        push_back
#define PI        acos(-1)
#define LC(a)     ((a<<1))
#define RC(a)     ((a<<1)+1)
#define MID(a,b)  ((a+b)>>1)
#define mem(a, b) memset(a, b, sizeof(a))
#define IOS()     std::ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
typedef long long ll;
typedef unsigned long long ULL;
typedef pair<int,int> PII;
typedef pair<ll,ll>   PLL;
typedef pair<ll,int>  PLI;
const int INF = 0X3F3F3F3F;
const int MIN = -(1<<30);
const ll N = 1e5+7;
inline void solve()
{
	double n;cin>>n;
	printf("%.6lf\n",n*PI*2);

}
int main()
{
	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

#include <bits/stdc++.h>
using namespace std;
int main (){cin.tie(0);
cin.sync_with_stdio(0);

double a=22.0/7.0,r;
cin>>r;
cout<<fixed<<setprecision(3)<<r*a*2;
}


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 i;
    double o;
    cin>>i;
    o = double(i*6.28318530717958623200);
    cout<<o<<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

/*This Code Is Nude*/
#include <bits/stdc++.h>
 
#define pb push_back
#define ll long long
#define int long long
#define max(a,b) max((long long) a , (long long) b)
#define min(a,b) min((long long) a , (long long) b)

using namespace std;

const int inf = 1e12 + 10; 
const int maxn = 2e5 + 10;
const int mod = 1e9 + 7;
 
bool mark [maxn];
vector<int>adj[maxn];

int32_t main(){
	ios:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int r;
	cin >> r;
	double p = 3.14;
	cout << r * 2 * p << endl;
	return 0;
}


Compiler output:
main.c:2:10: fatal error: bits/stdc++.h: No such file or directory
    2 | #include <bits/stdc++.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

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

int main()
{
    double r;
    cin >> r;
    
    double ans = r * 2 * 3.141592648777;
    cout << ans << 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>
using namespace std;

int main(){
	int r;
	float c;
	cin>>r;
	c=2*3.1415*r;
	cout<<fixed<<setprecision(3)<<(float)c;
	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;


int main()
{
    long double r;
    cin>>r;
    cout<< 2*M_PI*r;
}

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

K_s = input()
K = int(K_s)

print(2*K*3.1415926535)

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | K_s = input()
      | ^~~
main.c:1:1: error: type defaults to 'int' in declaration of 'K_s' [-Wimplicit-int]
main.c:1:7: error: implicit declaration of function 'input' [-Wimplicit-function-declaration]
    1 | K_s = input()
      |       ^~~~~
main.c:1:7: error: initializer element is not constant
main.c:2:1: error: expected ',' or ';' before 'K'
    2 | K = int(K_s)
      | ^
Language: C

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

int R;
long double pi = 3.14159265358979323846;

int main() {
  std::cin >> R;
  std::cout << std::fixed << std::setprecision(10) << 2*R*pi << std::endl;
}

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

#include<cstdio>
int main(){
  int a;
  scanf("%d",&a);
  double b;
  double pi;
  pi=3.141592653589793;
  b=a*2*pi;
  printf("%lf",b);
  return 0;
}

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

#include<bits/stdc++.h>
using namespace std;
int main(){
    int a;
    cin >> a;
    cout << 2*3.14159265358979*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<bits/stdc++.h>
using namespace std;
main()
{
  int n;
  cin>>n;
  double x=2*3.14*n;
  ccout << fixed << setprecision(20) <<x;
}

Compiler output:
a.cc:3:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    3 | main()
      | ^~~~
a.cc: In function 'int main()':
a.cc:8:3: error: 'ccout' was not declared in this scope
    8 |   ccout << fixed << setprecision(20) <<x;
      |   ^~~~~
Language: C

import math
R = int(input())
x = 2 * math.pi * R
print(x)

Compiler output:
main.c:1:1: error: unknown type name 'import'
    1 | import math
      | ^~~~~~
main.c:2:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'R'
    2 | R = int(input())
      | ^
Language: C

#include<iostream>
using namespace std;

int main(void)
{
	float PI=6.28318;
	float ans;
	int r;
	cin>>r;
	printf("%.2f",r*PI);
	return 0;
}

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

#include<iostream>
using namespace std;
typedef long long ll;
typedef long double ld;
const int mod=1000000007;
#define PI 3.1415926535
#define pb  push_back
#define FOR(i,n) for(int i=0;i<(n);i++)
#define FORA(i,a,b) for(int i=(a);i<=(b);i++)
#define FORD(i,a,b) for(int i=(a);i>=(b);i--)
#define FAST ios_base::sync_with_stdio(false);cin.tie(NULL);
#define count_1(n)  __builtin_popcountll(n)
#define parity(n)   __builtin_parityll(n)   //Even parity 0 as output
void show    (int a[], int arraysize) { for (int i = 0; i < arraysize; ++i)  {cout << a[i] << " ";}	cout<<endl;}
int gcd(int a, int b) { if (b == 0) return a; return gcd(b, a % b);}
void sieve(int n)
{
    bool prime[n+1];
    memset(prime, true, sizeof(prime));

    for (int p=2; p*p<=n; p++)
    {
        if (prime[p] == true)
        {
            for (int i=p*p; i<=n; i += p)
                prime[i] = false;
        }
    }
    for (int p=2; p<=n; p++)
       if (prime[p])
          cout << p << " ";
}
int main()
{FAST
double n;
cin>>n;
cout<< fixed << setprecision(5)<< 2*PI*n<<endl;

return  0;
}




Compiler output:
a.cc: In function 'void sieve(int)':
a.cc:19:5: error: 'memset' was not declared in this scope
   19 |     memset(prime, true, sizeof(prime));
      |     ^~~~~~
a.cc:2:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    1 | #include<iostream>
  +++ |+#include <cstring>
    2 | using namespace std;
a.cc: In function 'int main()':
a.cc:37:17: error: 'setprecision' was not declared in this scope
   37 | cout<< fixed << setprecision(5)<< 2*PI*n<<endl;
      |                 ^~~~~~~~~~~~
a.cc:2:1: note: 'std::setprecision' is defined in header '<iomanip>'; this is probably fixable by adding '#include <iomanip>'
    1 | #include<iostream>
  +++ |+#include <iomanip>
    2 | using namespace std;
Language: C

import numpy as np
R = input()
L = 2 * float(R) * np.pi
print(L)


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

int main()
{
	double r;
	scanf("%lf", &r);
	printf("%.2lf\n", r * 2 * 3.141592);
}


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 int long long int 
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector<int>
#define pi pair<int,int>
#define all(v) v.begin(),v.end()
#define zeros(arr) memset(arr,0,sizeof(arr));
#define precise(num)  cout<<fixed; cout << std::setprecision(num)
#define nl cout<<"\n";
int32_t main(){
    // boost;
    double pie ;
    pie =  3.141592653;
   
    double r;
    cin>>r;
    double ans = 2*pie*r;
    precise(10);
    cout<<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: C++

#include <bits/stdc++.h>
using namespace std;
 
int main(){
  int R;
  cin >>R;
  double A;
  A = 2*3.1415926535897*R
  cout<<A<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:26: error: expected ';' before 'cout'
    8 |   A = 2*3.1415926535897*R
      |                          ^
      |                          ;
    9 |   cout<<A<<endl;
      |   ~~~~
Language: C

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

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

  cout << 2 * M_PI * 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<bits/stdc++.h>
using namespace std;
int main(){
	double a,b;
	cin>>a;
	b=2*a*3.141*1.0;
	printf("%lf.\n"b);
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:16: error: unable to find string literal operator 'operator""b' with 'const char [6]', 'long unsigned int' arguments
    7 |         printf("%lf.\n"b);
      |                ^~~~~~~~~
Language: C

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define SORT(x) sort(x.begin(), x.end())
#define RS(x) rsort(x.begin(),x,end()))
#define REVE(x) reverse(x.begin(), x.end())
#define ALL(x) (x).begin(), (x).end()
typedef long double ld;
signed main(){
double R;
 cin >> R;
 cout << 2*R*M_PI; 
}


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<stdio.h>
#include<algorithm>
#include<iostream>
#include<stdlib.h>
using namespace std;


int main(){
  double PI=3.14159265358979323846;
  double R;scanf("%lf",&R);

  printf("%lf\n",2*PI*R);

  return 0;
}

Compiler output:
main.c:2:9: fatal error: algorithm: No such file or directory
    2 | #include<algorithm>
      |         ^~~~~~~~~~~
compilation terminated.
Language: C

c++ bits/stdc++.h

using namespace std;
 
    
    
int main(){
  int r;
  double x;
  cin>>r;
  x=2*3.14159265358979*r;
  cout<<x<<endl;
    return 0;
}

Compiler output:
main.c:1:2: error: expected '=', ',', ';', 'asm' or '__attribute__' before '++' token
    1 | c++ bits/stdc++.h
      |  ^~
main.c: In function 'main':
main.c:10:3: error: 'cin' undeclared (first use in this function)
   10 |   cin>>r;
      |   ^~~
main.c:10:3: note: each undeclared identifier is reported only once for each function it appears in
main.c:12:3: error: 'cout' undeclared (first use in this function)
   12 |   cout<<x<<endl;
      |   ^~~~
main.c:12:12: error: 'endl' undeclared (first use in this function)
   12 |   cout<<x<<endl;
      |            ^~~~
Language: C

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

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<pii> vii;
typedef vector<pll> vll;

const double PI = acos(-1);
#define MOD 1000000007

#define pb push_back
#define F first
#define S second
#define test int tc; cin>>tc; while(tc--)
#define forn(i,n) for(i=0;i<n;i++)
#define rforn(i,n) for(i=n-1;i>=0;i--)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sz(x) x.size()
#define el <<'\n'
#define sp <<' '

#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) (abs(a*b)/gcd(a,b))
#define sqr(a) (a*a)

#define optimize() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define file() freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);

main()
{
    ///optimize();
    double r;
    while(cin>>r){
        cout<<fixed<<setprecision(12)<<2*r*PI el;
    }






}





///Brainless people are gonna understand this code.




///Brainless_Loco Terminates Here!


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>
#define pi 3.141592653589793238
using namespace std;
int main(){
	double r;
	cin >> r;
	cout << 2 * r * pi;
	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<algorithm>
#include<vector>

#include<math.h>
typedef long long ll;
using namespace std;

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

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

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

import java.util.Scanner;
 
    public static void main(String[] args) {
        int R = 0;
        int sum = 0;
        Scanner scan = new Scanner(System.in);
        R = scan.nextInt();
        sum = R * 2 * 3.141592;
        System.out.println(sum);
        scan.close();
    }


Compiler output:
Main.java:3: error: unnamed classes are a preview feature and are disabled by default.
    public static void main(String[] args) {
                  ^
  (use --enable-preview to enable unnamed classes)
1 error
Language: Java

import java.util.Scanner;

public class circle_pond
{
    public static void main(String artg[])
    {
        Scanner in=new Scanner(System.in);
        int r=in.nextInt();
        System.out.println(Math.PI*2*r);
    }
}


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

package com.atc.abc163;

public class Solution100 {

	public static void main(String[] args) {
		System.out.println(1 * 2 * Math.PI);
	}

}


Compiler output:
Main.java:3: error: class Solution100 is public, should be declared in a file named Solution100.java
public class Solution100 {
       ^
1 error
Language: C

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

#define PI 3.1415926535

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

    cout << (double)N * (double)2.0 * (double)PI;

}


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

#define ll long long
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define mp make_pair
#define fo(i , n) for(ll i = 0 ; i < n ; i++)
#include<bits/stdc++.h>
//#include<iomanip>
#include<cmath>
#include<cstdio>
#include<utility>
#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<map>
#include<queue>
#include<set>
#include<stack>
double pi = acos(-1) ;
ll z =  1000000000 ;
ll inf = 6000000000000000000 ;
ll p1 = 37 ;
ll p2 = 53 ;
ll mod1 =  202976689 ;
ll mod2 =  203034253 ;
ll gcd(ll a , ll b){ if(b > a) return gcd(b , a) ; if(b == 0) return a ; return gcd(b , a%b) ;}
ll power(ll a ,ll b , ll p){if(b == 0) return 1 ; ll c = power(a , b/2 , p) ; if(b%2 == 0) return ((c*c)%p) ; else return ((((c*c)%p)*a)%p) ;}
ll inverse(ll a ,ll n){return power(a , n-2 , n) ;}
ll max(ll a , ll b){if(a > b) return a ; return b ;}
ll min(ll a , ll b){if(a < b) return a ; return b ;}
ll left(ll i){return ((2*i)+1) ;}
ll right(ll i){return ((2*i) + 2) ;}
void swap(ll&a , ll&b){ll c = a ; a = b ; b = c ; return ;}
//ios_base::sync_with_stdio(0);
//cin.tie(0); cout.tie(0);
using namespace std ;
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
using namespace __gnu_pbds; 
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
// ordered_set s ; s.order_of_key(val)  no. of elements strictly less than val
// s.find_by_order(i)  itertor to ith element (0 indexed)
//__builtin_popcount(n) -> returns number of set bits in n

void solve()
{
	ll n ;
	cin >> n ;
	cout << fixed << setprecision(10) << (2*pi*n) << endl ;
	return ;
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    /*#ifndef ONLINE_JUDGE
    freopen("inputf.txt" , "r" , stdin) ;
    freopen("outputf.txt" , "w" , stdout) ;
    freopen("error.txt" , "w" , stderr) ;
    #endif*/
    
    ll t ;
    //cin >> t ;
    t = 1 ;

    while(t--)
    {
        solve() ;
    }
    //cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC << "ms\n";
 
    return 0;
}

Compiler output:
main.c:8:9: fatal error: bits/stdc++.h: No such file or directory
    8 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define ll long long int 
#define endl '\n'
#define pb push_back
#define M 1000000007
#define sz(c) c.size()
#define mp make_pair
#define all(v) v.begin(),v.end()
#define rep(i,a,b) for(ll i=a;i<b;i++)
//const ll INF=2e18;

typedef vector<ll>   vi;
/*
bool isPrime(ll n){
	if(n<=1)
	return false;
	if(n<=3)
	return true;
	if(n%2==0 || n%3==0)
	return false;
	for(ll i=5;i*i<=n;i=i+6)
	{
		if(n%i==0 || n%(i+2)==0)
		return false;
	}
	return true;
}
*/
//bool sortbysec(const pair<char,ll> &a, const pair<char,ll> &b){
//	return (a.second<b.second);


void lucifer()
{
	ll n;
	cin>>n;
	cout<<2*(M_PI)*n;


}



signed main()
{
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);    
    ll t = 1;
    //clock_t start, end; 
    //start = clock(); 
 
    cout << fixed << setprecision(14);
   /* #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
    freopen("error.txt", "w", stderr);
    #endif*/
   //cin>>t;
    while(t--){
        lucifer();
    }
 
    //end = clock();
    //double time_taken = double(end - start) / double(CLOCKS_PER_SEC); 
    //cerr<<time_taken;
}

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 <iomanip>

using namespace std;

int main() {
  const float PI=3.14159265358979323846;
  float x;
  cin >> x;

  cout << setprecision(25) <<2.0 * PI * x << 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>

int main(){
	double pi = 3.141592;
	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

///mAAria...
#include<bits/stdc++.h>
 
using namespace std;
 
#define int long long
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define ld long double
#define ff first
#define ss second
#define pb push_back
#define pii pair<int,int>
#define pi 3.1415926535897932384626433832
#define mod 1000000000
//#define mod 998244353
#define inf 1000000000
#define pr1(a) cout << a << "\n"
#define pr2(a,b)cout << a <<  " " <<b<< "\n"
#define pr3(a,b,c) cout << a <<" " << b << " " << c << "\n"

const long double PI = acos(-1);

int powm(int a, int b) {
    int res=1;
    while(b) {
        if(b&1)
            res=(res*a)%mod;
        a=(a*a)%mod;
        b>>=1;
    }
    return res;
}

int gcd(int a, int b){
    if(b==0)return a;
    return gcd(b,a%b);
}
const int maxn = 2*1e5 + 10;


void solve(){
    int r;
    cin >> r;

    double ans = 2.0*(double)pi*(double)r;

    cout << fixed << setprecision(20) << ans << endl;
    

} 

signed main() 
{   
    IOS;
    int t = 1;
    // cin >> t;

    for(int i = 1;i<=t;i++){
        solve();
    }
    return 0;
} 

 


Compiler output:
main.c:2:9: fatal error: bits/stdc++.h: No such file or directory
    2 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C++

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

int main() {
  
  int R;
  cin >> R;
  
  double ans
  ans=2*R*3.14;
  cout << ans << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:3: error: expected initializer before 'ans'
   10 |   ans=2*R*3.14;
      |   ^~~
a.cc:11:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
   11 |   cout << ans << endl;
      |           ^~~
      |           abs
Language: C

＃include<stdio.h>
  
int main(void)
{
  int r;
  scanf("%d", &r);
  printf("%lf", 2 * 3.1415 * r);
  return 0;
}

Compiler output:
main.c:1:10: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
    1 | ＃include<stdio.h>
      |          ^
Language: C

#include <iostream>

using namespace std;

int main () 
{
  int a ,b;
  cin >> a;
  a *= 3.14159; 
  b = a * 2;
  cout << b << '\n';
  }


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