View Compilation Error

23214_0_10966.cpp:5: error: `main' must return `int'
23214_0_10966.cpp: In function `int main(...)':
23214_0_10966.cpp:7: error: `a' undeclared (first use this function)
23214_0_10966.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)
23214_0_10966.cpp:7: error: `b' undeclared (first use this function)
re \'