foo.c: In function 'main':
foo.c:8:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
    8 |  gets(a);
      |  ^~~~
In file included from /usr/include/stdio.h:867,
                 from foo.c:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:235:1: note: declared here
  235 | gets (char *__str)
      | ^~~~
foo.c:9:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
    9 |  gets(b);
      |  ^~~~
In file included from /usr/include/stdio.h:867,
                 from foo.c:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:235:1: note: declared here
  235 | gets (char *__str)
      | ^~~~
foo.c: In function 'Concat':
foo.c:17:4: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
   17 |  d=strlen(a);
      |    ^~~~~~
foo.c:17:4: warning: incompatible implicit declaration of built-in function 'strlen'
foo.c:2:1: note: include '<string.h>' or provide a declaration of 'strlen'
    1 | #include<stdio.h>
  +++ |+#include <string.h>
    2 | #include<stdio.h>
foo.c:23:2: warning: implicit declaration of function 'strcat' [-Wimplicit-function-declaration]
   23 |  strcat(c,b);
      |  ^~~~~~
foo.c:23:2: warning: incompatible implicit declaration of built-in function 'strcat'
foo.c:23:2: note: include '<string.h>' or provide a declaration of 'strcat'
foo.c: In function 'main':
foo.c:8:2: warning: ignoring return value of 'gets', declared with attribute warn_unused_result [-Wunused-result]
    8 |  gets(a);
      |  ^~~~~~~
foo.c:9:2: warning: ignoring return value of 'gets', declared with attribute warn_unused_result [-Wunused-result]
    9 |  gets(b);
      |  ^~~~~~~
/usr/bin/ld: /tmp/cczhEcdT.o: in function `main':
foo.c:(.text.startup+0x4e): warning: the `gets' function is dangerous and should not be used.

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