#include <stdio.h>
#include <signal.h>

main()
{	int i, acc;
	char ch;

	for(;;)
	{	acc = 0;
		for(i = 1; i <= 2; ++i)
		{	do	ch = getchar();
			while(ch == '\n' || ch == ' ');
			if(ch < 'A' || ch > 'P')
				exit(1);
			acc <<= 4;
			acc |= ch - 'A';
		}
		putchar(acc);
	}
	exit(0);
}