Main.c: In function ‘main’:
Main.c:13:21: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
   13 |         for(int i=0;strlen(arr)<=a;i++)
      |                     ^~~~~~
Main.c:13:21: warning: incompatible implicit declaration of built-in function ‘strlen’
Main.c:3:1: note: include ‘<string.h>’ or provide a declaration of ‘strlen’
    2 | #include <stdlib.h>
  +++ |+#include <string.h>
    3 | 
Main.c:17:12: warning: the address of ‘arr’ will always evaluate as ‘true’ [-Waddress]
   17 |         if(arr)
      |            ^~~
Main.c:18:5: error: expected expression before ‘}’ token
   18 |     }
      |     ^