View Compilation Error

816671_0_0_8928.cpp: In function `int main()':
816671_0_0_8928.cpp:21: error: `cin' undeclared (first use this function)
816671_0_0_8928.cpp:21: error: (Each undeclared identifier is reported only once for each function it appears in.)
816671_0_0_8928.cpp:40: error: `cout' undeclared (first use this function)
816671_0_0_8928.cpp:40: error: `endl' undeclared (first use this function)