View Compilation Error

255846_0_15023.cpp:2: error: `_int64' does not name a type
255846_0_15023.cpp: In function `int main()':
255846_0_15023.cpp:5: error: `num' undeclared (first use this function)
255846_0_15023.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)