Language: C++

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace std::chrono;
using namespace __gnu_pbds;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
#define INF 1e15
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)

typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector <ii> vii;
typedef vector<ll> vi;
typedef long double ld; 
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<int>::iterator sit;
typedef map<int,int>::iterator mit;
typedef vector<int>::iterator vit;

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n; cin >> n;
	ll x;
	ll ans = 1;
	bool zero = 0, exceed = 0;;
	for(int i = 0; i < n; i++){
		cin >> x; //cout << "*" << x << '\n';
		if(x == 0){
			zero = 1;
			break;
		}else if(x<=1e18/ans){
			ans*=x;
		}else{
			exceed = 1;
		}
	}
	if(zero){
		cout<<0<<'\n';
	}else if(exceed){
		cout<<-1<<'\n';
	}else{
		cout<<ans>>'\n';
	}
	
}


Compiler output:
a.cc: In function 'int main()':
a.cc:55:26: error: no match for 'operator>>' (operand types are 'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} and 'char')
   55 |                 cout<<ans>>'\n';
      |                 ~~~~~~~~~^~~~~~
      |                     |      |
      |                     |      char
      |                     std::basic_ostream<char>::__ostream_type {aka std::basic_ostream<char>}
a.cc:55:26: note: candidate: 'operator>>(int, int)' (built-in)
   55 |                 cout<<ans>>'\n';
      |                 ~~~~~~~~~^~~~~~
a.cc:55:26: note:   no known conversion for argument 1 from 'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} to 'int'
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:41,
                 from a.cc:1:
/usr/include/c++/14/cstddef:131:5: note: candidate: 'template<class _IntegerType> constexpr std::__byte_op_t<_IntegerType> std::operator>>(byte, _IntegerType)'
  131 |     operator>>(byte __b, _IntegerType __shift) noexcept
      |     ^~~~~~~~
/usr/include/c++/14/cstddef:131:5: note:   template argument deduction/substitution failed:
a.cc:55:21: note:   cannot convert 'std::cout.std::basic_ostream<char>::operator<<(ans)' (type 'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'}) to type 'std::byte'
   55 |                 cout<<ans>>'\n';
      |                 ~~~~^~~~~
In file included from /usr/include/c++/14/string:55,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/basic_string.tcc:835:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
  835 |     operator>>(basic_istream<_CharT, _Traits>& __in,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.tcc:835:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/bitset:1597:5: note: candidate: 'template<class _CharT, class _Traits, long unsigned int _Nb> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, bitset<_Nb>&)'
 1597 |     operator>>(std::basic_istream<_CharT, _Traits>& __is, bitset<_Nb>& __x)
      |     ^~~~~~~~
/usr/include/c++/14/bitset:1597:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
In file included from /usr/include/c++/14/istream:1109,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/bits/istream.tcc:978:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _CharT&)'
  978 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
      |     ^~~~~~~~
/usr/include/c++/14/bits/istream.tcc:978:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:849:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, unsigned char&)'
  849 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
      |     ^~~~~~~~
/usr/include/c++/14/istream:849:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<char, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:854:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, signed char&)'
  854 |     operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
      |     ^~~~~~~~
/usr/include/c++/14/istream:854:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<char, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:896:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _CharT*)'
  896 |     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
      |     ^~~~~~~~
/usr/include/c++/14/istream:896:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:939:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, unsigned char*)'
  939 |     operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/istream:939:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<char, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:945:5: note: candidate: 'template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(basic_istream<char, _Traits>&, signed char*)'
  945 |     operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
      |     ^~~~~~~~
/usr/include/c++/14/istream:945:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<char, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:1099:5: note: candidate: 'template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&)'
 1099 |     operator>>(_Istream&& __is, _Tp&& __x)
      |     ^~~~~~~~
/usr/include/c++/14/istream:1099:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/istream: In substitution of 'template<class _Istream, class _Tp> _Istream&& std::operator>>(_Istream&&, _Tp&&) [with _Istream = std::basic_ostream<char>&; _Tp = char]':
a.cc:55:14:   required from here
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/istream:1099:5: error: no type named 'type' in 'struct std::enable_if<false, void>'
 1099 |     operator>>(_Istream&& __is, _Tp&& __x)
      |     ^~~~~~~~
/usr/include/c++/14/complex:509:5: note: candidate: 'template<class _Tp, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, complex<_Tp>&)'
  509 |     operator>>(basic_istream<_CharT, _Traits>& __is, complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/include/c++/14/complex:509:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:143:
/usr/include/c++/14/iomanip:76:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Resetiosflags)'
   76 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Resetiosflags __f)
      |     ^~~~~~~~
/usr/include/c++/14/iomanip:76:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/iomanip:106:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setiosflags)'
  106 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setiosflags __f)
      |     ^~~~~~~~
/usr/include/c++/14/iomanip:106:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++/14/iomanip:137:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(basic_istream<_CharT, _Traits>&, _Setbase)'
  137 |     operator>>(basic_istream<_CharT, _Traits>& __is, _Setbase __f)
      |     ^~~~~~~~
/usr/include/c++/14/iomanip:137:5: note:   template argument deduction/substitution failed:
a.cc:55:28: note:   'std::basic_ostream<char>::__ostream_type' {aka 'std::basic_ostream<char>'} is not derived from 'std::basic_istream<_CharT, _Traits>'
   55 |                 cout<<ans>>'\n';
      |                            ^~~~
/usr/include/c++