View Compilation Error

0_0_17362769_31665.cpp: In function 'int main()':
0_0_17362769_31665.cpp:7:5: error: 'cin' was not declared in this scope
     cin>>t;  
     ^
0_0_17362769_31665.cpp:15:7: error: 'cout' was not declared in this scope
       cout<<sum<<endl;  
       ^
0_0_17362769_31665.cpp:15:18: error: 'endl' was not declared in this scope
       cout<<sum<<endl;  
                  ^