View Compilation Error

51243_0_32308.cpp:3: error: `main' must return `int'
51243_0_32308.cpp: In function `int main(...)':
51243_0_32308.cpp:4: error: `A' does not name a type
51243_0_32308.cpp:6: error: `A' undeclared (first use this function)
51243_0_32308.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
51243_0_32308.cpp:6: error: `B' undeclared (first use this function)