/in/foo.cc: In function 'int main()':
/in/foo.cc:21:2: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(s); cin>>c; 
  ^~~~
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:21:8: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(s); cin>>c; 
        ^
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/ccTJQTWE.o: In function `main':
foo.cc:(.text.startup+0x11): warning: the `gets' function is dangerous and should not be used.