Language: C++

nclude <bits/stdc++.h>
# define ll int64_t
#define rep(i,n) for(ll i=0;i<n;i++)
#define rrep(i,n) for(ll i=1;i<=n;i++)
# define ALL(x) (x).begin(), (x).end()
# define SZ(x) ((int)(x).size())
# define pb push_back

using namespace std;

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

bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
    if(a.first != b.first) return a.first<b.first;
    else return a.second<b.second;
}

bool my_compare(pair<string,ll> a,pair<string,ll> b){
    
    if(a.first != b.first) return a.first<b.first;
    if(a.second != b.second) return a.second>b.second;
    else return true;
}

int main(){
    ll n;
    cin>>n;
    if(n%2==0) cout<<n/2<<endl;
    else cout<<(n-1)/2 +1<<endl;
    return 0;
}

Compiler output:
a.cc:1:1: error: 'nclude' does not name a type
    1 | nclude <bits/stdc++.h>
      | ^~~~~~
a.cc:11:19: error: 'pair' was not declared in this scope
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                   ^~~~
a.cc:11:24: error: 'string' was not declared in this scope
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                        ^~~~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:11:31: note: in expansion of macro 'll'
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                               ^~
a.cc:1:1: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
  +++ |+#include <cstdint>
    1 | nclude <bits/stdc++.h>
a.cc:11:35: error: 'a' was not declared in this scope
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                   ^
a.cc:11:37: error: 'pair' was not declared in this scope
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                     ^~~~
a.cc:11:42: error: 'string' was not declared in this scope
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                          ^~~~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:11:49: note: in expansion of macro 'll'
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                                 ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:11:49: note: in expansion of macro 'll'
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                                 ^~
a.cc:11:53: error: 'b' was not declared in this scope; did you mean 'pb'?
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                                     ^
      |                                                     pb
a.cc:11:54: error: expression list treated as compound expression in initializer [-fpermissive]
   11 | bool compare_by_b(pair<string,ll> a,pair<string,ll> b){
      |                                                      ^
a.cc:16:19: error: 'pair' was not declared in this scope
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                   ^~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:24: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                        ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:24: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                        ^~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:27: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                           ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:27: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                           ^~
a.cc:16:31: error: 'a' was not declared in this scope
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                               ^
a.cc:16:33: error: 'pair' was not declared in this scope
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                 ^~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:38: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                      ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:38: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                      ^~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:41: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                         ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:16:41: note: in expansion of macro 'll'
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                         ^~
a.cc:16:45: error: 'b' was not declared in this scope; did you mean 'pb'?
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                             ^
      |                                             pb
a.cc:16:46: error: expression list treated as compound expression in initializer [-fpermissive]
   16 | bool compare_by_a(pair<ll,ll> a,pair<ll,ll> b){
      |                                              ^
a.cc:21:17: error: 'pair' was not declared in this scope
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                 ^~~~
a.cc:21:22: error: 'string' was not declared in this scope
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                      ^~~~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:21:29: note: in expansion of macro 'll'
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                             ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:21:29: note: in expansion of macro 'll'
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                             ^~
a.cc:21:33: error: 'a' was not declared in this scope
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                 ^
a.cc:21:35: error: 'pair' was not declared in this scope
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                   ^~~~
a.cc:21:40: error: 'string' was not declared in this scope
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                        ^~~~~~
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:21:47: note: in expansion of macro 'll'
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                               ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:21:47: note: in expansion of macro 'll'
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                               ^~
a.cc:21:51: error: 'b' was not declared in this scope; did you mean 'pb'?
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                                   ^
      |                                                   pb
a.cc:21:52: error: expression list treated as compound expression in initializer [-fpermissive]
   21 | bool my_compare(pair<string,ll> a,pair<string,ll> b){
      |                                                    ^
a.cc: In function 'int main()':
a.cc:2:13: error: 'int64_t' was not declared in this scope
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:29:5: note: in expansion of macro 'll'
   29 |     ll n;
      |     ^~
a.cc:2:13: note: 'int64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
    2 | # define ll int64_t
      |             ^~~~~~~
a.cc:29:5: note: in expansion of macro 'll'
   29 |     ll n;
      |     ^~
a.cc:30:5: error: 'cin' was not declared in this scope
   30 |     cin>>n;
      |     ^~~
a.cc:30:10: error: 'n' was not declared in this scope
   30 |     cin>>n;
      |          ^
a.cc:31:16: error: 'cout' was not declared in this scope
   31 |     if(n%2==0) cout<<n/2<<endl;
      |                ^~~~
a.cc:31:27: error: 'endl' was not declared in this scope
   31 |     if(n%2==0) cout<<n/2<<endl;
      |                           ^~~~
a.cc:32:10: error: 'cout' was not declared in this scope
   32 |     else cout<<(n-1)/2 +1<<endl;
      |          ^~~~
a.cc:32:28: error: 'endl' was not declared in this scope
   32 |     else cout<<(n-1)/2 +1<<endl;
      |                            ^~~~