View Compilation Error

0_0_38233683_21472.cpp: In function 'int mian()':
0_0_38233683_21472.cpp:6:4: error: 'cin' was not declared in this scope
    cin>>n;
    ^
0_0_38233683_21472.cpp:12:7: error: 'cout' was not declared in this scope
       cout<<sum<<endl;
       ^
0_0_38233683_21472.cpp:12:18: error: 'endl' was not declared in this scope
       cout<<sum<<endl;
                  ^