View Compilation Error

In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cassert:43:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/x86_64-w64-mingw32/bits/stdc++.h:33,
                 from 0_0_18393236_18572.cpp:1:
0_0_18393236_18572.cpp: In function 'void fwt(ll*, int, int)':
0_0_18393236_18572.cpp:10:8: error: 'x' was not declared in this scope
 assert(x <= 1e17); assert(y <= 1e17);
        ^
0_0_18393236_18572.cpp:10:27: error: 'y' was not declared in this scope
 assert(x <= 1e17); assert(y <= 1e17);
                           ^