View Compilation Error

0_0_11862730_22901.cpp:3: error: `_int64' does not name a type
0_0_11862730_22901.cpp: In function `void fun1(int)':
0_0_11862730_22901.cpp:15: error: `b' undeclared (first use this function)
0_0_11862730_22901.cpp:15: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11862730_22901.cpp:15: error: `a' undeclared (first use this function)
0_0_11862730_22901.cpp: In function `void fun2(int)':
0_0_11862730_22901.cpp:25: error: `a' undeclared (first use this function)
0_0_11862730_22901.cpp: In function `void fun3(int)':
0_0_11862730_22901.cpp:34: error: `a' undeclared (first use this function)
0_0_11862730_22901.cpp: In function `int main()':
0_0_11862730_22901.cpp:45: error: `a' undeclared (first use this function)