foo.cc: In function 'int main()':
foo.cc:12:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ~~~~~^~~~~~~~~~~~
foo.cc:42:6: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<ans;
  ~~~~^~~~~

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