View Compilation Error

0_0_33573673_21378.cpp: In function 'void solve()':
0_0_33573673_21378.cpp:45:35: error: wrong number of template arguments (0, should be 1)
     sort(c + 1, c + 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++/bits/locale_classes.h:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/ios_base.h:41,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ios:42,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ostream:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/iostream:39,
                 from 0_0_33573673_21378.cpp:2:
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>
            ^