foo.cc: In function 'int main()':
foo.cc:10:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&x);
  ~~~~~^~~~~~~~~
foo.cc:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld%lld",&fib[x],&fib[x-1],&fib[x-2]);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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