foo.c: In function 'main':
foo.c:7:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int n; scanf("%d", &n);
         ^~~~~~~~~~~~~~~
foo.c:8:12: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int x, y; scanf("%d", &x);
            ^~~~~~~~~~~~~~~
foo.c:15:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &y);
    ^~~~~~~~~~~~~~~

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