View Compilation Error

0_0_6186817_27433.cpp:3: error: `_int64' does not name a type
0_0_6186817_27433.cpp: In function `void f()':
0_0_6186817_27433.cpp:7: error: `a' undeclared (first use this function)
0_0_6186817_27433.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6186817_27433.cpp: In function `int main()':
0_0_6186817_27433.cpp:16: error: `a' undeclared (first use this function)