foo.c: In function 'Concat':
foo.c:6:72: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    6 |         for (i = strlen(s1) - 1, j = 1; i < strlen(s1) + strlen(s2) - 2, j < strlen(s2); j++, i++)
      |                                                                        ^
foo.c: In function 'main':
foo.c:16:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
   16 |         gets(s1);
      |         ^~~~
In file included from foo.c:1:
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.c:17:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
   17 |         gets(s2);
      |         ^~~~
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
/nix/store/3r87a2wq1w4l66wnsm7rqvy608mx23h6-binutils-2.40/bin/ld: /tmp/ccQjh8Wf.o: in function `main':
foo.c:(.text.startup+0xb): warning: the `gets' function is dangerous and should not be used.

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