/in/foo.cc: In function 'int main()':
/in/foo.cc:5:17: warning: right operand of comma operator has no effect [-Wunused-value]
    5 |         cin>>n,k;
      |                 ^
/in/foo.cc:4:21: warning: 'k' may be used uninitialized [-Wmaybe-uninitialized]
    4 |         long long n,k,sum,bot;
      |                     ^