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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_37728791_19245.cpp:1:
0_0_37728791_19245.cpp: In function 'void solve()':
0_0_37728791_19245.cpp:90:22: error: cannot convert 'vec3' to 'double' for argument '1' to 'int sgn(double)'
     assert(sgn(r1 - d) > 0);
                      ^