View Compilation Error

872500_0_0_1421.cpp: In function `int solve(int, long long int, int, int)':
872500_0_0_1421.cpp:6: error: `twoL' undeclared (first use this function)
872500_0_0_1421.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)