Error from Xcode making no sense to me????

I wanna study the C++ in XCode. After installing, I just inputted a following sample code,

#include <iostream>
using namespace std;

int main()
{
int iterations = 0;
bool continue_loop = true;
while ( continue_loop != false )
{
iterations++;
cout << "the while loop has executed "
<< iterations << " times\n";
if ( iterations == 5 )
continue_loop = false;
}
return 0;
}

but the XCode said "it is fail", the reason is
"duplicate symbol _main in /Users/roger/Documents/Try/build/Try.build/Debug/Try.build/Objects-normal/x86_64/Try.o and /Users/roger/Documents/Try/build/Try.build/Debug/Try.build/Objects-normal/x86_64/main.o"

so please help me, is it my mistake to install the xcode or open a wrong file, or some reasons.

Thank you very much..........

The error code actually makes perfect sense, you have 2 "main" functions which isn't allowed. Every program you create can only have one main function, because that's the function that is run FIRST when the application is run. Looks like you have possibly two files called "Try.cpp" and "main.cpp"??

How did you create the XCode project for your test?

Regards