#include <stdio.h>

int	main(int argc, char *argv[])
{
	int	ch1, ch2;

	while ((ch1 = getchar()) != EOF && (ch2 = getchar()) != EOF) {
		putchar(ch1);
		putchar(ch2);
		putchar(ch1);
		putchar(ch2);
	}

	return 0;
}