foo.c: In function 'main':
foo.c:6:1: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d",&n);
 ^~~~~~~~~~~~~~
foo.c:7:1: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d",&a,&b);
 ^~~~~~~~~~~~~~~~~~~
foo.c:12:1: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d",&a,&b);
 ^~~~~~~~~~~~~~~~~~~

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