View Compilation Error

285342_0_5123.cpp: In function `int main()':
285342_0_5123.cpp:6: error: `cin' undeclared (first use this function)
285342_0_5123.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
285342_0_5123.cpp:15: error: `sqrt' undeclared (first use this function)
285342_0_5123.cpp:19: error: `cout' undeclared (first use this function)
285342_0_5123.cpp:19: error: `endl' undeclared (first use this function)