Language: C++

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

/* REPmacro */
#define REP(i,n) for(int i=0,i##_len=(n);i<i##_len;++i)
#define REPR(i,n) for(int i=((int)(n)-1);i>=0;--i)
#define FOR(i,m,n) for(int i=(int)(m);i<=(int)(n);++i)

/*alias*/
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define F first
#define S second
#define PB push_back
#define MP make_pair 

#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
#define next asdnext
#define prev asdprev

/*using*/
using ll = long long;
using ull = unsigned long long;
using unsi = unsigned;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using pii = pair<int, int>;
using db = double;
using plex = complex<double>;
using vs = vector<string>;

/*template*/
template<class T>inline bool amax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>inline bool amin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

/* func */
int gcd(int a,int b){return b?gcd(b,a%b):a;}

/*struct*/
struct aaa{
    aaa(){
        cin.tie(0); ios::sync_with_stdio(0); cout<<fixed<<setprecision(20);
    };
}aaaaaaa;

/* const */
const int INF = 1001001001;
const ll LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7; //10^9
const db EPS = 1e-9;
const int dx[] = {0, 1, 0, -1, 1, -1, 1, -1}, dy[] = {1, 0, -1, 0, 1, -1, -1, 1};

//#define int ll
//#define int long long

signed main()
{
	int n;
  	cin >> n;
  
  　int exp = log2(n);
  
  cout << pow(2,exp);
  return 0;
}

Compiler output:
a.cc:65:3: error: extended character 　 is not valid in an identifier
   65 |   　int exp = log2(n);
      |   ^
a.cc: In function 'int main()':
a.cc:65:3: error: '\U00003000int' was not declared in this scope
   65 |   　int exp = log2(n);
      |   ^~~~~
a.cc:67:14: error: no matching function for call to 'pow(int, <unresolved overloaded function type>)'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166,
                 from a.cc:1:
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_Constant, std::_ValArray, _Tp, _Tp>, _Tp> std::pow(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::valarray<_Tp>' and 'float(float)'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
a.cc:67:14: note:   mismatched types 'const std::valarray<_Tp>' and 'long double(long double)'
a.cc:67:14: note:   mismatched types 'const std::valarray<_Tp>' and 'double(double) noexcept'
a.cc:67:14: note:   couldn't deduce template parameter '_Tp'
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_ValArray, std::_Constant, _Tp, _Tp>, _Tp> std::pow(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_ValArray, std::_ValArray, _Tp, _Tp>, _Tp> std::pow(const valarray<_Tp>&, const valarray<_Tp>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename _Dom::value_type> std::pow(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'float(float)'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'long double(long double)'
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'double(double) noexcept'
a.cc:67:14: note:   couldn't deduce template parameter '_Dom'
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename _Dom::value_type> std::pow(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename _Dom::value_type> std::pow(const valarray<typename _Dom::valarray>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'float(float)'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'long double(long double)'
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'double(double) noexcept'
a.cc:67:14: note:   couldn't deduce template parameter '_Dom'
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename _Dom::value_type> std::pow(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::_Pow, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename _Dom1::value_type> std::pow(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  549 | _DEFINE_EXPR_BINARY_FUNCTION(pow, struct std::_Pow)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:549:1: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/complex:2482:5: note: candidate: 'template<class _Tp, class _Up> std::complex<typename __gnu_cxx::__promote<decltype (((typename __gnu_cxx::__promote<_Tp, std::__is_integer<_Tp>::__value>::__type)(0) + (typename __gnu_cxx::__promote<_Up, std::__is_integer<_Up>::__value>::__type)(0)))>::__type> std::pow(const complex<_Tp>&, const complex<_Up>&)'
 2482 |     pow(const std::complex<_Tp>& __x, const std::complex<_Up>& __y)
      |     ^~~
/usr/include/c++/14/complex:2482:5: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/complex:2474:5: note: candidate: 'template<class _Tp, class _Up> std::complex<typename __gnu_cxx::__promote<decltype (((typename __gnu_cxx::__promote<_Tp, std::__is_integer<_Tp>::__value>::__type)(0) + (typename __gnu_cxx::__promote<_Up, std::__is_integer<_Up>::__value>::__type)(0)))>::__type> std::pow(const _Tp&, const complex<_Up>&)'
 2474 |     pow(const _Tp& __x, const std::complex<_Up>& __y)
      |     ^~~
/usr/include/c++/14/complex:2474:5: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::complex<_Up>' and 'float(float)'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
a.cc:67:14: note:   mismatched types 'const std::complex<_Up>' and 'long double(long double)'
a.cc:67:14: note:   mismatched types 'const std::complex<_Up>' and 'double(double) noexcept'
a.cc:67:14: note:   couldn't deduce template parameter '_Up'
/usr/include/c++/14/complex:2466:5: note: candidate: 'template<class _Tp, class _Up> std::complex<typename __gnu_cxx::__promote<decltype (((typename __gnu_cxx::__promote<_Tp, std::__is_integer<_Tp>::__value>::__type)(0) + (typename __gnu_cxx::__promote<_Up, std::__is_integer<_Up>::__value>::__type)(0)))>::__type> std::pow(const complex<_Tp>&, const _Up&)'
 2466 |     pow(const std::complex<_Tp>& __x, const _Up& __y)
      |     ^~~
/usr/include/c++/14/complex:2466:5: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/complex:1339:5: note: candidate: 'std::complex<_Tp> std::pow(const _Tp&, const complex<_Tp>&) [with _Tp = int]'
 1339 |     pow(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~
/usr/include/c++/14/complex:1339:45: note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'const std::complex<int>&'
 1339 |     pow(const _Tp& __x, const complex<_Tp>& __y)
      |                         ~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/complex:1328:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::pow(const complex<_Tp>&, const complex<_Tp>&)'
 1328 |     pow(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~
/usr/include/c++/14/complex:1328:5: note:   template argument deduction/substitution failed:
a.cc:67:14: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   67 |   cout << pow(2,exp);
      |           ~~~^~~~~~~
/usr/include/c++/14/complex:1294:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::pow(const complex<_Tp>&, const _Tp&)'
 1294 |     pow(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~
/usr/include/c++/14/complex:1294:5: note:   template argument dedu