/in/foo.c: In function 'main':
/in/foo.c:7:2: 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:20:6: warning: unused variable 'k' [-Wunused-variable]
  int k=0;
      ^
/in/foo.c:16:6: warning: unused variable 'max' [-Wunused-variable]
  int max[26];  int m=count[0];
      ^~~
/in/foo.c:6:9: warning: unused variable 't' [-Wunused-variable]
  int i, t=0;
         ^
/tmp/ccyZnRmh.o: In function `main':
foo.c:(.text.startup+0x18): warning: the `gets' function is dangerous and should not be used.