View Compilation Error

0_0_8508034_32009.cpp: In function `int main()':
0_0_8508034_32009.cpp:12: error: `a' undeclared (first use this function)
0_0_8508034_32009.cpp:12: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8508034_32009.cpp:14: error: `b' undeclared (first use this function)
0_0_8508034_32009.cpp:22: error: `c' undeclared (first use this function)