foo.c: In function 'main':
foo.c:21:30: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
   21 |                 hash[j]+=min(abs(j-a[i]),abs(26-abs(j-a[i])));
      |                              ^~~
foo.c:3:1: note: include '<stdlib.h>' or provide a declaration of 'abs'
    2 | #include<math.h>
  +++ |+#include <stdlib.h>
    3 | 

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