/in/foo.cc: In function 'int main()':
/in/foo.cc:8:11: warning: unused variable 'n' [-Wunused-variable]
     int i,n;
           ^
/in/foo.cc: At global scope:
/in/foo.cc:18:1: error: expected unqualified-id before 'return'
 return 0;
 ^~~~~~