/in/foo.c: In function 'main':
/in/foo.c:7:3: warning: 'gets' is deprecated [-Wdeprecated-declarations]
   gets(s);
   ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:26:8: warning: array subscript has type 'char' [-Wchar-subscripts]
    if(b[j]==max)
        ^
/in/foo.c:4:15: warning: unused variable 'a' [-Wunused-variable]
   int i=0,max,a;
               ^
/tmp/ccXvvBMz.o: In function `main':
foo.c:(.text.startup+0x37): warning: the `gets' function is dangerous and should not be used.