foo.cc: In function 'int main()':
foo.cc:6:10: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>a,b;
          ^
foo.cc:7:10: error: no match for call to '(std::ostream {aka std::basic_ostream<char>}) (int)'
  cout(a+b)<<endl; 
          ^

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