/in/foo.c: In function 'main':
/in/foo.c:21:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
  gets(a);
  ^~~~
In file included from /in/foo.c:2:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:92:3: error: 'cout' undeclared (first use in this function)
   cout<<maxn-minn;
   ^~~~
/in/foo.c:92:3: note: each undeclared identifier is reported only once for each function it appears in