foo.c: In function 'main':
foo.c:15:2: warning: statement with no effect [-Wunused-value]
  for(i;i<n&&cnt==2;i+=2)
  ^~~
foo.c:9:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j=0,cnt=n;
        ^
foo.c:8:8: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int n;scanf("%d",&n);
        ^~~~~~~~~~~~~~
foo.c:11:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ^~~~~~~~~~~~~~~~~

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