foo.c: In function 'main':
foo.c:4:23: warning: unused variable 'y' [-Wunused-variable]
  int n,a[103],i,j,f=0,y=1,x=0;
                       ^
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
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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