View Compilation Error

851118_0_0_503.cpp: In function `int main()':
851118_0_0_503.cpp:5: error: expected init-declarator before "scanf"
851118_0_0_503.cpp:5: error: expected `,' or `;' before "scanf"
851118_0_0_503.cpp:7: error: `b' undeclared (first use this function)
851118_0_0_503.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)