foo.cpp:1:1: error: 'include' does not name a type
 include<iostream> 
 ^
foo.cpp: In function 'int main()':
foo.cpp:11:2: error: 'cin' was not declared in this scope
  cin>>a;
  ^
foo.cpp:13:18: error: 'sort' was not declared in this scope
  sort(num+0,num+a);
                  ^
foo.cpp:25:2: error: 'cout' was not declared in this scope
  cout<<result;
  ^