/in/ex5.cpp: In member function 'void bookInventory::removeBook(int)':
/in/ex5.cpp:35:22: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (ID < 1 || ID > numBooks) {
                   ~~~^~~~~~~~~~
/in/ex5.cpp:38:24: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for (int i = ID; i < numBooks; ++i) {
                      ~~^~~~~~~~~~
cc1plus: all warnings being treated as errors
/in/compile/Makefile:26: recipe for target 'ex5.o' failed
make: *** [ex5.o] Error 1