foo.c: In function 'main':
foo.c:171:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ^~~~~~~~~~~~~~~~~~~~~
foo.c:173:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &arr[i]);
   ^~~~~~~~~~~~~~~~~~~~
foo.c:179:14: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   int k,a,b; scanf("%d%d%d", &k, &a, &b);
              ^~~~~~~~~~~~~~~~~~~~~~~~~~~

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