View Compilation Error

0_0_6643179_29940.cpp: In function `int main()':
0_0_6643179_29940.cpp:16: error: `n' undeclared (first use this function)
0_0_6643179_29940.cpp:16: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6643179_29940.cpp:19: error: `x' undeclared (first use this function)