Language: C++

#include <iostream>

int main()
{
????????????
std: :cin >> x;

x=x*x*x;

std: :cout << x;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:1: error: expected primary-expression before '?' token
    5 | ????????????
      | ^
a.cc:5:2: error: expected primary-expression before '?' token
    5 | ????????????
      |  ^
a.cc:5:3: error: expected primary-expression before '?' token
    5 | ????????????
      |   ^
a.cc:5:4: error: expected primary-expression before '?' token
    5 | ????????????
      |    ^
a.cc:5:5: error: expected primary-expression before '?' token
    5 | ????????????
      |     ^
a.cc:5:6: error: expected primary-expression before '?' token
    5 | ????????????
      |      ^
a.cc:5:7: error: expected primary-expression before '?' token
    5 | ????????????
      |       ^
a.cc:5:8: error: expected primary-expression before '?' token
    5 | ????????????
      |        ^
a.cc:5:9: error: expected primary-expression before '?' token
    5 | ????????????
      |         ^
a.cc:5:10: error: expected primary-expression before '?' token
    5 | ????????????
      |          ^
a.cc:5:11: error: expected primary-expression before '?' token
    5 | ????????????
      |           ^
a.cc:5:12: error: expected primary-expression before '?' token
    5 | ????????????
      |            ^
a.cc:6:4: error: expected primary-expression before ':' token
    6 | std: :cin >> x;
      |    ^
a.cc:6:6: error: expected primary-expression before ':' token
    6 | std: :cin >> x;
      |      ^
a.cc:6:7: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 | std: :cin >> x;
      |       ^~~
      |       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:6:14: error: 'x' was not declared in this scope
    6 | std: :cin >> x;
      |              ^
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:6:15: error: expected ':' before ';' token
    6 | std: :cin >> x;
      |               ^
      |               :
a.cc:6:15: error: expected primary-expression before ';' token
a.cc:10:6: error: expected primary-expression before ':' token
   10 | std: :cout << x;
      |      ^