Run id: 121857

Main.cc: In function 'int main()':
Main.cc:7:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^
Main.cc:20:13: error: 'cout' was not declared in this scope
             cout<<"-1";
             ^
Main.cc:29:5: error: 'cout' was not declared in this scope
     cout<