foo.cc: In function 'int main()':
foo.cc:11:10: warning: unused variable 'k1' [-Wunused-variable]
   11 |  int k=0,k1=0;
      |          ^~
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
foo.cc:9:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    9 |   scanf("%d",&a[i]);
      |   ~~~~~^~~~~~~~~~~~

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