Language: C++

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

typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<ll,ll> pii;
typedef vector<pii> vpii;

#define pb(x) push_back(x)
#define ppb() pop_back()
#define mp(x,y) make_pair(x,y)
#define mod 1000000007
#define FOR0(i,n) for(ll i=0;i<n;i++)
#define FOR(i,a,b) for(ll i = a; i < b; i++)
#define FORD(i,a,b) for(ll i=(a);i>=(int)(b);i--)
#define sf(n) scanf("%lld", &n)
#define sfc(x) scanf("%c", &x)
#define pf(x) printf("%lld", x)
#define pff(x) printf("%lf", x)
#define pfc(x) printf("%c", x)
#define pfs(x) printf("%s", x)
#define sf2(a,b) scanf("%lld %lld", &a, &b)
#define sf3(a,b,c) scanf("%lld %lld %lld", &a, &b, &c)
#define pfn(n) printf("%lld\n", n)
#define pfs(n) printf("%lld ", n)
#define ff first
#define ss second
#define mem(a,b) memset(a,b,sizeof(a))
#define sz size()
#define ll long long
#define all(c) (c).begin(),(c).end()
#define fast ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
const ll INF = 2e18;

bool prime[1000009];
//unordered_map<ll,ll> largest_factor;
void SieveOfEratosthenes(ll n)
{
    memset(prime,true, sizeof(prime));

    for (ll p=2; p*p<=n; p++)
    {
        if (prime[p] == true)
        {
            for (ll i=p*p; i<=n; i += p){
                prime[i] = false;
                //largest_factor[i]=p;
            }

        }
    }
}


ll power(ll x,ll y)
{
    if (y == 0)
        return 1;
    else if (y%2 == 0)
        return power(x, y/2)*power(x, y/2);
    else
        return x*power(x, y/2)*power(x, y/2);
}

ll power1(ll a,ll b){
    ll res=1;
    while(b){
        if(b&1){
            res*=a;
        }
        a=a*a;
        b>>=1;
    }
    return res;
}



ll mod_power(ll a,ll b,ll m){
    ll res=1;
    a%=m;
    while(b){
        if(b&1){
            res=res*a%m;
        }
        a=a*a%m;
        b>>=1;
    }
    return res;
}
ll printDivisors(ll n)
{
    ll count=0;
    for (ll i=1; i<=sqrt(n); i++)
    {
        if (n%i == 0)
        {
            if (n/i == i)
                count++;

            else // Otherwise print both
                printf("%d %d ", i, n/i);
        }
    }
}
bool isPrime(int n)
{
    if (n <= 1)  return false;
    if (n <= 3)  return true;

    if (n%2 == 0 || n%3 == 0) return false;

    for (int i=5; i*i<=n; i=i+6)
        if (n%i == 0 || n%(i+2) == 0)
           return false;

    return true;
}
// vector<pii> v[10001];
// ll vis[10001]={0};
//  ll dis[10001];
// void dijkstra(){
//     FOR0(i,10001)dis[i]=1e18;
//     multiset<pii > s;
//     s.insert({0,1});
//     dis[1]=0;
//     while(!s.empty()){
//         pii up = *s.begin();
//         ll u=up.ss;
//         s.erase(s.begin());
//         if(vis[u])continue;
//         vis[u]=1;
//         FOR0(i,v[u].size()){
//             ll e = v[u][i].ff,w=v[u][i].ss;
//             if(dis[u]+w<dis[e]){
//                 dis[e]=dis[u]+w;
//                 s.insert({dis[e],e});
//             }
//         }
//     }

// }

// void dijkstra(ll s){
//         FOR0(i,10001)dis[i]=INF;
//         dis[s] = 0;
//         priority_queue<pii , vpii , greater<pii >> pq;
//         //priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
//         pq.push({0, s});
//         while(!pq.empty())
//         {
//             int u = pq.top().ss;
//             //int d = pq.top().first;
//             pq.pop();
//             if(vis[u]) continue;
//             vis[u] = 1;
//             for(auto it: v[u])
//             {
//                 int e = it.ff;
//                 int w = it.ss;
//                 if(dis[u] + w < dis[e])
//                 {
//                     dis[e] = dis[u] + w;
//                     pq.push({dis[e], e});
//                 }
//             }
//         }
// }

// void dfs1(ll s,ll count){
//     vis[s]=1;
//     //val[s]=count;
//     FOR0(i,v[s].size()){
//         if(!vis[v[s][i]]){
//             dfs1(v[s][i],count);
//         }
//     }
// }

// void dfs(ll s){
//     stack<ll> st;
//     st.push(s);
//     vis[s]=1;
//     while(!st.empty()){
//         ll u = st.top();
//         st.pop();
//         FOR0(i,v[u].size()){
//             if(!vis[v[u][i]]){
//                 st.push(v[u][i]);
//                 vis[v[u][i]]=1;
//             }
//         }
//     }
// }


// ll bs(){
//     ll l,h,mid;
//     while(l<=h){
//         mid = (l+h)/2;
//         if(a[mid]==x)return mid;
//         else if(x>a[mid]){
//             l = mid+1;
//         }
//         else if(x<a[mid]){
//             h = mid-1;
//         }
//     }
// }

// ll lbs(){
//     ll l,h,mid;
//     while(l<h){
//         mid = (l+h)/2;
//         if(x<=a[mid]){
//             h = mid;
//         }
//         else{
//             l = mid-1;
//         }
//     }
//     if(a[l]==x)return l;
//     else return -1;
// }

// ll ubs(){
//     ll l,h,mid;
//     while(l<h){
//         mid = (l+h)/2;
//         if(a[mid]<=x)l = mid;
//         else{
//             h = mid-1;
//         }
//     }
//     if(a[h]==x)return h;
//     else return -1;
// }
ll min(ll a,ll b){
    if(a<b)return a;
    else return b;
}

ll d,x,y;

void extendedEuclid(ll a,ll b){
    if(b==0){
        d = a;
        x = 1;
        y = 0;
        extendedEuclid(b,a%b);
    }
    else{
        ll temp = x;
        x = y;
        y = temp - (a/b)*y;
    }
}

ll stringmod(string s,ll m){
    ll res = 0;
    FOR0(i,s.length()){
        res = (res*10 + (ll)s[i]-'0')%m;
    }
    return res;
}

ll fact[200005];

ll nCr(ll n,ll r){
    ll ans = fact[n];
    ans = (ans*mod_power(fact[n-r],mod-2,mod))%mod;
    ans%=mod;
    //ans = (ans*mod_power(fact[r],mod-2,mod))%mod;
    ans%=mod;
    return ans;
}

bool compare(const pair<ll,string> &a, 
              const pair<ll,string> &b) 
{ 
    if(a.first==b.first)
        return (a.second < b.second);
    else
        return (a.first>b.first);
}

ll min4(ll a,ll b,ll c,ll d){
    return min(min(a,b),min(c,d));
}

ll par[100001];
ll size[100001]={0};
ll maxi=0;
ll find(ll x){
    if(par[x]!=x){
        par[x] = find(par[x]);
    }
    return par[x];
}

void unionset(ll x,ll y){
    ll xr = find(x);
    ll yr = find(y);

    if(size[xr]>=size[yr]){
        par[yr]=xr;
        size[xr]+=size[yr];
        size[yr]=0;
        maxi = max(maxi,size[xr]);
    }
    else{
        par[xr]=yr;
        size[yr]+=size[xr];
        size[xr]=0;
        maxi = max(maxi,size[yr]);
    }
}


int main(){
    fast
    ll x;
    cin>>x;
    couot<<3*x*x<<endl;
}

Compiler output:
a.cc:27:9: warning: "pfs" redefined
   27 | #define pfs(n) printf("%lld ", n)
      |         ^~~
a.cc:23:9: note: this is the location of the previous definition
   23 | #define pfs(x) printf("%s", x)
      |         ^~~
a.cc: In function 'long long int printDivisors(long long int)':
a.cc:107:1: warning: no return statement in function returning non-void [-Wreturn-type]
  107 | }
      | ^
a.cc: In function 'void unionset(long long int, long long int)':
a.cc:307:8: error: reference to 'size' is ambiguous
  307 |     if(size[xr]>=size[yr]){
      |        ^~~~
In file included from /usr/include/c++/14/string:53,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52,
                 from a.cc:1:
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:307:18: error: reference to 'size' is ambiguous
  307 |     if(size[xr]>=size[yr]){
      |                  ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:309:9: error: reference to 'size' is ambiguous
  309 |         size[xr]+=size[yr];
      |         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:309:19: error: reference to 'size' is ambiguous
  309 |         size[xr]+=size[yr];
      |                   ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:310:9: error: reference to 'size' is ambiguous
  310 |         size[yr]=0;
      |         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:311:25: error: reference to 'size' is ambiguous
  311 |         maxi = max(maxi,size[xr]);
      |                         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:315:9: error: reference to 'size' is ambiguous
  315 |         size[yr]+=size[xr];
      |         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:315:19: error: reference to 'size' is ambiguous
  315 |         size[yr]+=size[xr];
      |                   ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:316:9: error: reference to 'size' is ambiguous
  316 |         size[xr]=0;
      |         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc:317:25: error: reference to 'size' is ambiguous
  317 |         maxi = max(maxi,size[yr]);
      |                         ^~~~
/usr/include/c++/14/bits/range_access.h:272:5: note: candidates are: 'template<class _Tp, long unsigned int _Nm> constexpr std::size_t std::size(const _Tp (&)[_Nm])'
  272 |     size(const _Tp (&)[_Nm]) noexcept
      |     ^~~~
/usr/include/c++/14/bits/range_access.h:262:5: note:                 'template<class _Container> constexpr decltype (__cont.size()) std::size(const _Container&)'
  262 |     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
      |     ^~~~
a.cc:294:4: note:                 'long long int size [100001]'
  294 | ll size[100001]={0};
      |    ^~~~
a.cc: In function 'int main()':
a.cc:326:5: error: 'couot' was not declared in this scope
  326 |     couot<<3*x*x<<endl;
      |     ^~~~~