Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <cstring>
#include <math.h>
#include <bitset>
#include <queue>
#include <set>
#include <iomanip>
#include <math.h>
#include <assert.h>
// #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr long long int INFLL = 1001001001001001LL;
constexpr long long int infll = 1001001001001001LL;
constexpr int INF = 1000000007;
constexpr int inf = 1000000007;
const int mod = 1000000007;

template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}

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

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

inline double nCr(const int n, int r)
{
    if (n == 0)
    {
        return 0;
    }
    if (r == 0)
    {
        return 1;
    }
    if (r == 1)
    {
        return n;
    }
    if (n == r)
    {
        return 1;
    }

    if (r > n / 2)
    {
        r = n / 2;
    }

    double result = 1;
    for (double i = 1; i <= r; i++)
    {
        result *= (n - i + 1) / i;
    }

    return (result);
}

template <typename T>
T seinomi(T a)
{
    if (a > 0)
    {
        return a;
    }
    else
    {
        return 0;
    }
}

template <typename T>
map<T, T> soinsuubunkai(T n) //連想配列[素因数f.first][個数f.second]
{
    map<T, T> ret;
    for (T i = 2; i * i <= n; i++)
    {
        while (n % i == 0)
        {
            ret[i]++;
            n /= i;
        }
    }
    if (n != 1)
        ret[n] = 1;
    return ret;
}

template <typename T>
T ketasuu(T num)
{
    return std::to_string(num).length();
}

int kaizyou(int k)
{
    int sum = 1;
    for (int i = 1; i <= k; ++i)
    {
        sum *= i;
    }
    return sum;
}

template <class ForwardIt, class T>
void iota(ForwardIt first, ForwardIt last, T value)
{
    while (first != last)
    {
        *first++ = value;
        ++value;
    }
}

//nの階乗を計算
int factorial(int n)
{
    int answer = 1;
    while (n > 1)
    {
        answer *= n;
        n--;
    }
    return answer;
}
int comb(int n, int r)
{
    return factorial(n) / (factorial(r) * factorial(n - r));
}

long long modpow(long long a, long long n, long long mod)
{
    long long res = 1;
    while (n > 0)
    {
        if (n & 1)
            res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

//小数点以下10桁テンプレート（main関数内の最初に貼付け）
//std::cout << std::fixed << std::setprecision(10);

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


int main(){
ll n;
cin>>n;
cout<<n/3<<endl;
}







#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <cstring>
#include <math.h>
#include <bitset>
#include <queue>
#include <set>
#include <iomanip>
#include <math.h>
#include <assert.h>
// #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr long long int INFLL = 1001001001001001LL;
constexpr long long int infll = 1001001001001001LL;
constexpr int INF = 1000000007;
constexpr int inf = 1000000007;
const int mod = 1000000007;

template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}

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

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

inline double nCr(const int n, int r)
{
    if (n == 0)
    {
        return 0;
    }
    if (r == 0)
    {
        return 1;
    }
    if (r == 1)
    {
        return n;
    }
    if (n == r)
    {
        return 1;
    }

    if (r > n / 2)
    {
        r = n / 2;
    }

    double result = 1;
    for (double i = 1; i <= r; i++)
    {
        result *= (n - i + 1) / i;
    }

    return (result);
}

template <typename T>
T seinomi(T a)
{
    if (a > 0)
    {
        return a;
    }
    else
    {
        return 0;
    }
}

template <typename T>
map<T, T> soinsuubunkai(T n) //連想配列[素因数f.first][個数f.second]
{
    map<T, T> ret;
    for (T i = 2; i * i <= n; i++)
    {
        while (n % i == 0)
        {
            ret[i]++;
            n /= i;
        }
    }
    if (n != 1)
        ret[n] = 1;
    return ret;
}

template <typename T>
T ketasuu(T num)
{
    return std::to_string(num).length();
}

int kaizyou(int k)
{
    int sum = 1;
    for (int i = 1; i <= k; ++i)
    {
        sum *= i;
    }
    return sum;
}

template <class ForwardIt, class T>
void iota(ForwardIt first, ForwardIt last, T value)
{
    while (first != last)
    {
        *first++ = value;
        ++value;
    }
}

//nの階乗を計算
int factorial(int n)
{
    int answer = 1;
    while (n > 1)
    {
        answer *= n;
        n--;
    }
    return answer;
}
int comb(int n, int r)
{
    return factorial(n) / (factorial(r) * factorial(n - r));
}

long long modpow(long long a, long long n, long long mod)
{
    long long res = 1;
    while (n > 0)
    {
        if (n & 1)
            res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

//小数点以下10桁テンプレート（main関数内の最初に貼付け）
//std::cout << std::fixed << std::setprecision(10);

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


int main(){
ll n;
cin>>n;
cout<<n/3<<endl;
}









Compiler output:
a.cc:211:25: error: redefinition of 'constexpr const long long int INFLL'
  211 | constexpr long long int INFLL = 1001001001001001LL;
      |                         ^~~~~
a.cc:16:25: note: 'constexpr const long long int INFLL' previously defined here
   16 | constexpr long long int INFLL = 1001001001001001LL;
      |                         ^~~~~
a.cc:212:25: error: redefinition of 'constexpr const long long int infll'
  212 | constexpr long long int infll = 1001001001001001LL;
      |                         ^~~~~
a.cc:17:25: note: 'constexpr const long long int infll' previously defined here
   17 | constexpr long long int infll = 1001001001001001LL;
      |                         ^~~~~
a.cc:213:15: error: redefinition of 'constexpr const int INF'
  213 | constexpr int INF = 1000000007;
      |               ^~~
a.cc:18:15: note: 'constexpr const int INF' previously defined here
   18 | constexpr int INF = 1000000007;
      |               ^~~
a.cc:214:15: error: redefinition of 'constexpr const int inf'
  214 | constexpr int inf = 1000000007;
      |               ^~~
a.cc:19:15: note: 'constexpr const int inf' previously defined here
   19 | constexpr int inf = 1000000007;
      |               ^~~
a.cc:215:11: error: redefinition of 'const int mod'
  215 | const int mod = 1000000007;
      |           ^~~
a.cc:20:11: note: 'const int mod' previously defined here
   20 | const int mod = 1000000007;
      |           ^~~
a.cc:218:13: error: redefinition of 'template<class T> bool chmin(T&, T)'
  218 | inline bool chmin(T &a, T b)
      |             ^~~~~
a.cc:23:13: note: 'template<class T> bool chmin(T&, T)' previously declared here
   23 | inline bool chmin(T &a, T b)
      |             ^~~~~
a.cc:228:13: error: redefinition of 'template<class T> bool chmax(T&, T)'
  228 | inline bool chmax(T &a, T b)
      |             ^~~~~
a.cc:33:13: note: 'template<class T> bool chmax(T&, T)' previously declared here
   33 | inline bool chmax(T &a, T b)
      |             ^~~~~
a.cc:238:4: error: redefinition of 'll gcd(ll, ll)'
  238 | ll gcd(ll a, ll b)
      |    ^~~
a.cc:43:4: note: 'll gcd(ll, ll)' previously defined here
   43 | ll gcd(ll a, ll b)
      |    ^~~
a.cc:250:4: error: redefinition of 'll lcm(ll, ll)'
  250 | ll lcm(ll a, ll b)
      |    ^~~
a.cc:55:4: note: 'll lcm(ll, ll)' previously defined here
   55 | ll lcm(ll a, ll b)
      |    ^~~
a.cc:255:15: error: redefinition of 'double nCr(int, int)'
  255 | inline double nCr(const int n, int r)
      |               ^~~
a.cc:60:15: note: 'double nCr(int, int)' previously defined here
   60 | inline double nCr(const int n, int r)
      |               ^~~
a.cc:289:3: error: redefinition of 'template<class T> T seinomi(T)'
  289 | T seinomi(T a)
      |   ^~~~~~~
a.cc:94:3: note: 'template<class T> T seinomi(T)' previously declared here
   94 | T seinomi(T a)
      |   ^~~~~~~
a.cc:302:11: error: redefinition of 'template<class T> std::map<T, T> soinsuubunkai(T)'
  302 | map<T, T> soinsuubunkai(T n) //連想配列[素因数f.first][個数f.second]
      |           ^~~~~~~~~~~~~
a.cc:107:11: note: 'template<class T> std::map<T, T> soinsuubunkai(T)' previously declared here
  107 | map<T, T> soinsuubunkai(T n) //連想配列[素因数f.first][個数f.second]
      |           ^~~~~~~~~~~~~
a.cc:319:3: error: redefinition of 'template<class T> T ketasuu(T)'
  319 | T ketasuu(T num)
      |   ^~~~~~~
a.cc:124:3: note: 'template<class T> T ketasuu(T)' previously declared here
  124 | T ketasuu(T num)
      |   ^~~~~~~
a.cc:324:5: error: redefinition of 'int kaizyou(int)'
  324 | int kaizyou(int k)
      |     ^~~~~~~
a.cc:129:5: note: 'int kaizyou(int)' previously defined here
  129 | int kaizyou(int k)
      |     ^~~~~~~
a.cc:335:6: error: redefinition of 'template<class ForwardIt, class T> void iota(ForwardIt, ForwardIt, T)'
  335 | void iota(ForwardIt first, ForwardIt last, T value)
      |      ^~~~
a.cc:140:6: note: 'template<class ForwardIt, class T> void iota(ForwardIt, ForwardIt, T)' previously declared here
  140 | void iota(ForwardIt first, ForwardIt last, T value)
      |      ^~~~
a.cc:345:5: error: redefinition of 'int factorial(int)'
  345 | int factorial(int n)
      |     ^~~~~~~~~
a.cc:150:5: note: 'int factorial(int)' previously defined here
  150 | int factorial(int n)
      |     ^~~~~~~~~
a.cc:355:5: error: redefinition of 'int comb(int, int)'
  355 | int comb(int n, int r)
      |     ^~~~
a.cc:160:5: note: 'int comb(int, int)' previously defined here
  160 | int comb(int n, int r)
      |     ^~~~
a.cc:360:11: error: redefinition of 'long long int modpow(long long int, long long int, long long int)'
  360 | long long modpow(long long a, long long n, long long mod)
      |           ^~~~~~
a.cc:165:11: note: 'long long int modpow(long long int, long long int, long long int)' previously defined here
  165 | long long modpow(long long a, long long n, long long mod)
      |           ^~~~~~
a.cc:379:5: error: redefinition of 'int main()'
  379 | int main(){
      |     ^~~~
a.cc:184:5: note: 'int main()' previously defined here
  184 | int main(){
      |     ^~~~