foo.cc: In function 'int main()':
foo.cc:5:6: warning: unused variable 'n' [-Wunused-variable]
    5 |  int n,i,k,cnt=0;
      |      ^
foo.cc:5:10: warning: unused variable 'k' [-Wunused-variable]
    5 |  int n,i,k,cnt=0;
      |          ^

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