/in/foo.cc: In function 'int main()':
/in/foo.cc:6:2: error: 'cout' was not declared in this scope
  cout <<(0~100);
  ^~~~
/in/foo.cc:6:11: error: expected ')' before '~' token
  cout <<(0~100);
           ^
/in/foo.cc:7:2: error: 'cin' was not declared in this scope
  cin >>a;
  ^~~