foo.cc: In function 'int main()':
foo.cc:5:7: warning: unused variable 'i' [-Wunused-variable]
    5 |   int i,j,k,n,ans=0,x=1;
      |       ^
foo.cc:5:9: warning: unused variable 'j' [-Wunused-variable]
    5 |   int i,j,k,n,ans=0,x=1;
      |         ^
foo.cc:6:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 |   scanf("%d%d",&k,&n);
      |   ~~~~~^~~~~~~~~~~~~~

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