Language: C++

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

using ll = int64_t;
#define int ll

#define for(i, a, b) for (int i = int(a); i < int(b); i++)
#define rep(i, b) for(i, 0, b)
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
auto &errstream = cerr;
#ifdef local
#define cerr (cerr << "-- line " << __line__ << " -- ")
#else
class cerrdummy {
} cerrdummy;
template <class t> cerrdummy &operator<<(cerrdummy &cd, const t &) {
  return cd;
}
using chartdummy = char;
using traitsdummy = char_traits<chartdummy>;
cerrdummy &operator<<(cerrdummy &cd,
                      basic_ostream<chartdummy, traitsdummy> &(
                          basic_ostream<chartdummy, traitsdummy> &)) {
  return cd;
}
#define cerr cerrdummy
#endif
#define reach cerr << "reached" << endl
#define dmp(x) cerr << #x << ":" << x << endl
#define zero(x) memset(x, 0, sizeof(x))
#define one(x) memset(x, -1, sizeof(x))

using pi = pair<int, int>;
using vi = vector<int>;
using ld = long double;

template <class t, class u>
ostream &operator<<(ostream &os, const pair<t, u> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

template <class t> ostream &operator<<(ostream &os, const vector<t> &v) {
  os << "{";
  rep(i, (int)v.size()) {
    if (i)
      os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}

ll read() {
  ll i;
  scanf("%" scnd64, &i);
  return i;
}

void printspace() { printf(" "); }

void printeoln() { printf("\n"); }

void print(ll x, int suc = 1) {
  printf("%" prid64, x);
  if (suc == 1)
    printeoln();
  if (suc == 2)
    printspace();
}

string readstring() {
  static char buf[3341000];
  scanf("%s", buf);
  return string(buf);
}

char *readchararray() {
  static char buf[3341000];
  static int bufused = 0;
  char *ret = buf + bufused;
  scanf("%s", ret);
  bufused += strlen(ret) + 1;
  return ret;
}

template <class t, class u> void chmax(t &a, u b) {
  if (a < b)
    a = b;
}

template <class t, class u> void chmin(t &a, u b) {
  if (b < a)
    a = b;
}

template <class t> t sq(const t &t) { return t * t; }

#define capital
void yes(bool ex = true) {
#ifdef capital
  cout << "yes" << endl;
#else
  cout << "yes" << endl;
#endif
  if (ex)
    exit(0);
}
void no(bool ex = true) {
#ifdef capital
  cout << "no" << endl;
#else
  cout << "no" << endl;
#endif
  if (ex)
    exit(0);
}

const ll infll = llong_max / 3;

#ifdef int
const int inf = infll;
#else
const int inf = int_max / 2 - 100;
#endif

signed main() {
  int a = read();

  if (a < 1200)
    cout << "abc" << endl;
  else
    cout << "arc" << endl;

  return 0;
}

Compiler output:
a.cc:20:20: error: 'cerrdummy' does not name a type
   20 | template <class t> cerrdummy &operator<<(cerrdummy &cd, const t &) {
      |                    ^~~~~~~~~
a.cc:25:1: error: 'cerrdummy' does not name a type
   25 | cerrdummy &operator<<(cerrdummy &cd,
      | ^~~~~~~~~
a.cc: In function 'll read()':
a.cc:60:12: error: expected ')' before 'scnd64'
   60 |   scanf("%" scnd64, &i);
      |        ~   ^~~~~~~
      |            )
a.cc: In function 'void print(ll, ll)':
a.cc:69:13: error: expected ')' before 'prid64'
   69 |   printf("%" prid64, x);
      |         ~   ^~~~~~~
      |             )
a.cc: At global scope:
a.cc:101:34: error: declaration of 'const t& t' shadows template parameter
  101 | template <class t> t sq(const t &t) { return t * t; }
      |                         ~~~~~~~~~^
a.cc:101:11: note: template parameter 't' declared here
  101 | template <class t> t sq(const t &t) { return t * t; }
      |           ^~~~~
a.cc: In function 't sq(const t&)':
a.cc:101:34: error: declaration of 'const t& t' shadows template parameter
  101 | template <class t> t sq(const t &t) { return t * t; }
      |                         ~~~~~~~~~^
a.cc:101:11: note: template parameter 't' declared here
  101 | template <class t> t sq(const t &t) { return t * t; }
      |           ^~~~~
a.cc: At global scope:
a.cc:123:18: error: 'llong_max' was not declared in this scope
  123 | const ll infll = llong_max / 3;
      |                  ^~~~~~~~~