View Compilation Error

158941_0_7668.cpp: In function `int main()':
158941_0_7668.cpp:11: error: `x' undeclared (first use this function)
158941_0_7668.cpp:11: error: (Each undeclared identifier is reported only once for each function it appears in.)
158941_0_7668.cpp:14: error: `a' undeclared (first use this function)