View Compilation Error

0_0_21724421_28607.cpp: In function 'int main()':
0_0_21724421_28607.cpp:7:8: error: 'cin' was not declared in this scope
  while(cin>>n&&n){
        ^
0_0_21724421_28607.cpp:16:3: error: 'cout' was not declared in this scope
   cout<<sum<<endl;
   ^
0_0_21724421_28607.cpp:16:14: error: 'endl' was not declared in this scope
   cout<<sum<<endl;
              ^