/in/foo.c: In function 'main':
/in/foo.c:6:17: error: 'xin' undeclared (first use in this function)
  scanf("%d%d", &xin,&xmax);
                 ^~~
/in/foo.c:6:17: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:15:9: warning: missing terminating " character
  printf("%d\n, sum);
         ^
/in/foo.c:15:9: error: missing terminating " character
  printf("%d\n, sum);
         ^~~~~~~~~~~~
/in/foo.c:16:2: error: expected expression before 'return'
  return 0
  ^~~~~~
/in/foo.c:17:1: error: expected ';' before '}' token
 }
 ^