View Compilation Error

0_0_31146653_2386.cpp: In function 'int main()':
0_0_31146653_2386.cpp:5:11: error: 'cin' was not declared in this scope
     while(cin>>n)
           ^
0_0_31146653_2386.cpp:15:9: error: 'cout' was not declared in this scope
         cout<<b<<endl;
         ^
0_0_31146653_2386.cpp:15:18: error: 'endl' was not declared in this scope
         cout<<b<<endl;
                  ^