/in/foo.cc: In function 'int main()':
/in/foo.cc:13:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s);
     ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/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(s);
           ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:17:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(flag2<strlen(s))
           ~~~~~^~~~~~~~~~
/in/foo.cc:19:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      while(flag2<strlen(s)&&s[flag2]!=' ') flag2++;
            ~~~~~^~~~~~~~~~
/in/foo.cc:23:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      if(flag2==strlen(s))
         ~~~~~^~~~~~~~~~~
/tmp/cczA17jb.o: In function `main':
foo.cc:(.text.startup+0x29): warning: the `gets' function is dangerous and should not be used.