foo.c: In function 'main':
foo.c:4:11: warning: unused variable 'n' [-Wunused-variable]
 { int m,i,n,r;
           ^
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&m);
  ^~~~~~~~~~~~~~
foo.c:8:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ^~~~~~~~~~~~~~~~~

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