View Compilation Error

0_0_3326414_15625.cpp: In function `int main()':
0_0_3326414_15625.cpp:28: error: `ix' undeclared (first use this function)
0_0_3326414_15625.cpp:28: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_3326414_15625.cpp:28: error: `iy' undeclared (first use this function)