foo.cc: In function 'int main()':
foo.cc:4:2: error: 'cin' was not declared in this scope
  cin>>a>>b;
  ^~~
foo.cc:4:2: note: suggested alternative: 'main'
  cin>>a>>b;
  ^~~
  main
foo.cc:5:2: error: 'cout' was not declared in this scope
  cout<<a+b; 
  ^~~~

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