/in/foo.c: In function 'main':
/in/foo.c:53:1: 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:54:1: warning: 'gets' is deprecated [-Wdeprecated-declarations]
 gets(b);
 ^~~~
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:52:13: warning: unused variable 'j' [-Wunused-variable]
 int i,len=0,j; 
             ^
/in/foo.c:52:5: warning: unused variable 'i' [-Wunused-variable]
 int i,len=0,j; 
     ^
/tmp/ccxBrsoe.o: In function `main':
foo.c:(.text.startup+0x22): warning: the `gets' function is dangerous and should not be used.