/in/foo.cc: In function 'bool com()':
/in/foo.cc:14:4: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
 if (a[0]==k[0])
    ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:43:1: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
 gets(st+1);
 ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 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:43:10: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
 gets(st+1);
          ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 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: In function 'bool com()':
/in/foo.cc:16:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/tmp/cccqHHgf.o: In function `main':
foo.cc:(.text.startup+0xc): warning: the `gets' function is dangerous and should not be used.