View Compilation Error

0_0_37148617_6625.cpp: In function 'int main()':
0_0_37148617_6625.cpp:5:1: error: 'cin' was not declared in this scope
 cin >> n;
 ^
0_0_37148617_6625.cpp:9:1: error: 'cout' was not declared in this scope
 cout << sum << endl;
 ^
0_0_37148617_6625.cpp:9:16: error: 'endl' was not declared in this scope
 cout << sum << endl;
                ^