View Compilation Error

0_0_13215729_20925.cpp: In function 'int main()':
0_0_13215729_20925.cpp:7:19: error: 'cin' was not declared in this scope
     int t; while( cin>>t ){
                   ^
0_0_13215729_20925.cpp:11:9: error: 'cout' was not declared in this scope
         cout << sum << endl;
         ^
0_0_13215729_20925.cpp:11:24: error: 'endl' was not declared in this scope
         cout << sum << endl;
                        ^