#include<stdio.h>
#include<string.h>
int main()
{
	char str[10000];
	gets(str);
	int flag1=1;
	int flag2=1;
	int len=strlen(str);
	int i;
	for(i=0;i<len;i++)
	{
	if(i%2==0)//i是偶数，这是第奇数 个数字 
	{
		if(!(str[i]=='R'||str[i]=='U'||str[i]=='D'))
		{
			printf("No\n");
			printf("The %d-rd character is not R, U, nor D, so S is not easily playable.",i+1);
			flag1=0;
			break;
		}
	}
	if(i%2==1)
	{
		if(!(str[i]=='L'||str[i]=='U'||str[i]=='D'))
		{
			printf("No\n");
			printf("The %d-rd character is not L, U, nor D, so S is not easily playable.",i+1);
			flag2=0;
			break;
		}
	}
    }
    if(flag1==1&&flag2==1)
	{
		printf("YES\n");
		printf("Every character in an odd position (1-st, 3-rd, 5-th, 7-th) is R, U, or D.\n");
        printf("Every character in an even position (2-nd, 4-th, 6-th) is L, U, or D.\n");
        printf("Thus, S is easily playable.\n");
	 } 
	return 0;
 } 