View Compilation Error

177495_0_31545.cpp:3: error: `main' must return `int'
177495_0_31545.cpp: In function `int main(...)':
177495_0_31545.cpp:5: error: `$a' undeclared (first use this function)
177495_0_31545.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
177495_0_31545.cpp:5: error: `$b' undeclared (first use this function)