#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define maxLength 80

int main()
{
	char str[maxLength];
	char tmp[]="CFUK";
	char temp[maxLength];
	int length,n;
	int i,j;
	int flag;
	gets (str);
	length = strlen(str);
	i = 0;
	while (i<length)
	{
		if (isalpha(str[i]))
		{
			j = 0;
			strcpy (temp,"");
			flag = 1;
			while (i<length && isalpha(str[i]))
			{
				temp[j++] = str[i];
				i++;
			}
			temp[j] = '\0';
			n = strlen(temp);
			for (j=0; j<n; j++)
				if (!strchr(tmp,temp[j]))
				{
					flag = 0;
					break;
				}
			if (flag)
				printf ("%s\n",temp);
		}
		else ++i;
	}
	return 0;
}