View Compilation Error

0_0_4075142_14897.cpp:9: error: `int64' does not name a type
0_0_4075142_14897.cpp: In function `int main()':
0_0_4075142_14897.cpp:18: error: `a' undeclared (first use this function)
0_0_4075142_14897.cpp:18: error: (Each undeclared identifier is reported only once for each function it appears in.)