#include <iostream>
#include <iomanip>   //for setfill and setw
#include <cstdlib>
using namespace std;

int main()
{
	double d = 1.0;
	unsigned char c = *reinterpret_cast<unsigned char *>(&d);

	cout << "The first byte of the double is 0x"
		<< hex << setfill('0') << setw(2)
		<< static_cast<unsigned>(c) << ".\n";

	return EXIT_SUCCESS;
}