View Compilation Error

0_0_1271520_15287.cpp: In function `int F(int, int, int, int, float, float)':
0_0_1271520_15287.cpp:39: error: `x' undeclared (first use this function)
0_0_1271520_15287.cpp:39: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1271520_15287.cpp:39: error: `y' undeclared (first use this function)