View Compilation Error

0_0_18099787_28054.cpp: In function 'int main()':
0_0_18099787_28054.cpp:13:13: error: 'max' was not declared in this scope
    m=max(m,x);
             ^
0_0_18099787_28054.cpp:13:13: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62:0,
                 from 0_0_18099787_28054.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:3454:5: note:   'std::max'
     max(initializer_list<_Tp> __l, _Compare __comp)
     ^