View Compilation Error

0_0_4391081_4305.cpp: In function `void Solve()':
0_0_4391081_4305.cpp:38: error: `HA' undeclared (first use this function)
0_0_4391081_4305.cpp:38: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4391081_4305.cpp:38: error: `HB' undeclared (first use this function)
0_0_4391081_4305.cpp:38: error: `ZA' undeclared (first use this function)
0_0_4391081_4305.cpp:38: error: `ZB' undeclared (first use this function)