/in/foo.cc: In function 'int main()':
/in/foo.cc:12:2: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(str1);
  ^~~~
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:12:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(str1);
           ^
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:13:2: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(str2);
  ^~~~
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:13:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(str2);
           ^
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:10:6: warning: unused variable 'sum3' [-Wunused-variable]
  int sum3=0;
      ^~~~
/in/foo.cc:11:6: warning: unused variable 'sum4' [-Wunused-variable]
  int sum4=0;
      ^~~~
/tmp/ccJPtwIB.o: In function `main':
foo.cc:(.text.startup+0x15): warning: the `gets' function is dangerous and should not be used.