View Compilation Error

0_0_1366229_14332.cpp: In function `void solve()':
0_0_1366229_14332.cpp:49: error: `occ' undeclared (first use this function)
0_0_1366229_14332.cpp:49: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1366229_14332.cpp:58: error: `bt' undeclared (first use this function)