foo.cc: In function 'int main()':
foo.cc:6:10: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |  cin>>n,k;
      |          ^
foo.cc:5:8: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
    5 |  int n,k;
      |        ^

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