View Compilation Error

0_0_14720626_2448.cpp:1:1: error: 'include' does not name a type
 include <iostream>
 ^
0_0_14720626_2448.cpp: In function 'int main()':
0_0_14720626_2448.cpp:39:30: error: 'swap' was not declared in this scope
                     swap(a, b); 
                              ^