View Compilation Error

0_0_6595084_3661.cpp: In function `int main()':
0_0_6595084_3661.cpp:29: error: `a' undeclared (first use this function)
0_0_6595084_3661.cpp:29: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6595084_3661.cpp:29: error: `b' undeclared (first use this function)
0_0_6595084_3661.cpp:29: error: initializer expression list treated as compound expression
0_0_6595084_3661.cpp:40: error: `f' cannot be used as a function