View Compilation Error

0_0_21428079_15137.cpp: In function 'int main()':
0_0_21428079_15137.cpp:19:5: error: 'cin' was not declared in this scope
     cin>>t;
     ^
0_0_21428079_15137.cpp:38:13: error: 'cout' was not declared in this scope
             cout<<"Case #"<<j<<':'<<' '<<sum<<endl; 
             ^
0_0_21428079_15137.cpp:38:47: error: 'endl' was not declared in this scope
             cout<<"Case #"<<j<<':'<<' '<<sum<<endl; 
                                               ^