Language: C++

#include <iostream>
#include <vector>
#include <algorithm>

using ll = long long
using namespace std;

ll gcd( ll m, ll n )
{
	if (n == 0) return m;
	else return gcd(n, m%n);
}//gcd

//*********************************************************
// 最小公倍数（Least Common Multiple）を返す。
// 引数に０がある場合は０を返す。
//*********************************************************
ll lcm( ll m, ll n )
{
	ll g = gcd(m, n);
	return (m / g * n); // lcm = m * n / gcd(m,n)
}//lcm

int main() {
    ll N;
    cin>>N;
    ll ans = 1;
    for (ll n = 0; n < N; n++) {
        ll T;
        cin>>T;
        ans = lcm(ans, T);
    }
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc:5:21: error: expected ';' before 'using'
    5 | using ll = long long
      |                     ^
      |                     ;
    6 | using namespace std;
      | ~~~~~                
a.cc:8:1: error: 'll' does not name a type
    8 | ll gcd( ll m, ll n )
      | ^~
a.cc:18:1: error: 'll' does not name a type
   18 | ll lcm( ll m, ll n )
      | ^~
a.cc: In function 'int main()':
a.cc:25:5: error: 'll' was not declared in this scope
   25 |     ll N;
      |     ^~
a.cc:26:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
   26 |     cin>>N;
      |     ^~~
      |     std::cin
In file included 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:26:10: error: 'N' was not declared in this scope
   26 |     cin>>N;
      |          ^
a.cc:27:7: error: expected ';' before 'ans'
   27 |     ll ans = 1;
      |       ^~~~
      |       ;
a.cc:28:12: error: expected ';' before 'n'
   28 |     for (ll n = 0; n < N; n++) {
      |            ^~
      |            ;
a.cc:28:20: error: 'n' was not declared in this scope
   28 |     for (ll n = 0; n < N; n++) {
      |                    ^
a.cc:29:11: error: expected ';' before 'T'
   29 |         ll T;
      |           ^~
      |           ;
a.cc:30:14: error: 'T' was not declared in this scope
   30 |         cin>>T;
      |              ^
a.cc:31:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   31 |         ans = lcm(ans, T);
      |         ^~~
      |         abs
a.cc:31:15: error: 'lcm' was not declared in this scope
   31 |         ans = lcm(ans, T);
      |               ^~~
a.cc:33:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   33 |     cout<<ans<<endl;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:33:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
   33 |     cout<<ans<<endl;
      |           ^~~
      |           abs
a.cc:33:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   33 |     cout<<ans<<endl;
      |                ^~~~
      |                std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~