Run id: 120881

Main.cc: In function 'int main()':
Main.cc:8:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^
Main.cc:22:9: error: 'cout' was not declared in this scope
         cout<<"-1";
         ^
Main.cc:31:5: error: 'cout' was not declared in this scope
     cout<