View Compilation Error

0_0_4869905_27992.cpp:3: error: `_int64' does not name a type
0_0_4869905_27992.cpp: In function `int main()':
0_0_4869905_27992.cpp:9: error: `a' undeclared (first use this function)
0_0_4869905_27992.cpp:9: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4869905_27992.cpp:10: error: `b' undeclared (first use this function)