View Compilation Error

0_0_15003149_27923.cpp: In function 'int main()':
0_0_15003149_27923.cpp:63:29: error: 'min' was not declared in this scope
             mn = min(now, mn);
                             ^
0_0_15003149_27923.cpp:63:29: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62:0,
                 from 0_0_15003149_27923.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:3444:5: note:   'std::min'
     min(initializer_list<_Tp> __l, _Compare __comp)
     ^