/tmp/ccO0aqU0.o: In function `query()':
grader.cpp:(.text+0x30): multiple definition of `query()'
/tmp/cc3tcn1I.o:Xoractive.cpp:(.text+0x30): first defined here
/tmp/ccO0aqU0.o: In function `ask(int)':
grader.cpp:(.text+0x60): multiple definition of `ask(int)'
/tmp/cc3tcn1I.o:Xoractive.cpp:(.text+0x60): first defined here
/tmp/ccO0aqU0.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/cc3tcn1I.o:Xoractive.cpp:(.text.startup+0x0): first defined here
/tmp/ccO0aqU0.o: In function `get_pairwise_xor(std::vector<int, std::allocator<int> >)':
grader.cpp:(.text+0xc0): multiple definition of `get_pairwise_xor(std::vector<int, std::allocator<int> >)'
/tmp/cc3tcn1I.o:Xoractive.cpp:(.text+0xd0): first defined here
collect2: error: ld returned 1 exit status