View Compilation Error

0_0_38012310_3085.cpp: In function 'int main()':
0_0_38012310_3085.cpp:47:34: error: wrong number of template arguments (0, should be 1)
   sort(l + 1, l + n + 1, greater<>());
                                  ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/string:48:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/stdexcept:39,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/array:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/tuple:39,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/unordered_map:41,
                 from 0_0_38012310_3085.cpp:1:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_function.h:358:12: error: provided for 'template<class _Tp> struct std::greater'
     struct greater : public binary_function<_Tp, _Tp, bool>
            ^