/in/foo.cc: In function 'int main()':
/in/foo.cc:11:15: error: unable to find numeric literal operator 'operator""n'
 for(int i=n;i<2n;i++)
               ^~
/in/foo.cc:11:15: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes