/in/foo.c: In function 'main':
/in/foo.c:11:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
  gets(a);
  ^~~~
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:16:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(a[i]>='A'&&a[i]<=('A'+m-1)||a[i]>='a'&&a[i]<=('a'+m-1))
      ~~~~~~~~~^~~~~~~~~~~~~~~~~
/in/foo.c:21:19: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(a[i]>=('A'+m)&&a[i]<='Z'||a[i]>=('a'+m)&&a[i]<='z')
      ~~~~~~~~~~~~~^~~~~~~~~~~
/tmp/cc0OB2IM.o: In function `main':
foo.c:(.text.startup+0x11): warning: the `gets' function is dangerous and should not be used.