/in/foo.cc: In function 'int main()':
/in/foo.cc:18:16: error: expected ';' before ':' token
   18 |             l++:
      |                ^
      |                ;
/in/foo.cc:7:5: warning: label 'std' defined but not used [-Wunused-label]
    7 |     std:ios::sync_with_stdio(false);
      |     ^~~