/in/foo.cc: In function 'int perb(int, int)':
/in/foo.cc:7:12: error: expected primary-expression before ',' token
  if(n == 0), return 1;
            ^
/in/foo.cc:7:14: error: expected primary-expression before 'return'
  if(n == 0), return 1;
              ^~~~~~