View Compilation Error

1_277_4005_12161.cpp: In function `void pre()':
1_277_4005_12161.cpp:34: error: `cout' undeclared (first use this function)
1_277_4005_12161.cpp:34: error: (Each undeclared identifier is reported only once for each function it appears in.)
1_277_4005_12161.cpp:34: error: `endl' undeclared (first use this function)