View Compilation Error

0_0_32582299_23822.cpp: In function 'int main()':
0_0_32582299_23822.cpp:4:11: error: 'cin' was not declared in this scope
     while(cin >> a){
           ^
0_0_32582299_23822.cpp:10:9: error: 'cout' was not declared in this scope
         cout << sum << endl;
         ^
0_0_32582299_23822.cpp:10:24: error: 'endl' was not declared in this scope
         cout << sum << endl;
                        ^