View Compilation Error

0_0_30328627_16857.cpp: In function 'int main()':
0_0_30328627_16857.cpp:8:15: error: 'cin' was not declared in this scope
         while(cin>>n>>B>>D>>f>>F)
               ^
0_0_30328627_16857.cpp:30:17: error: 'cout' was not declared in this scope
                 cout<<time_min<<endl;
                 ^
0_0_30328627_16857.cpp:30:33: error: 'endl' was not declared in this scope
                 cout<<time_min<<endl;
                                 ^