View Compilation Error

0_0_14284816_27928.cpp: In function 'int main()':
0_0_14284816_27928.cpp:11:3: error: 'sort' is not a member of 'std'
   std::sort(a,a+n);
   ^
0_0_14284816_27928.cpp:14:3: error: 'sort' is not a member of 'std'
   std::sort(b,b+m);
   ^