#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
int main()
{
const int n = 26;
char sys_26[2][26];
char name[2][30];
for (int i = 0; i < n; i++)
{
sys_26[0][i] = 'a' + i;
sys_26[1][i] = i;
}
while (scanf("%s%s",name[0],name[1]) != EOF && name[0][0]-48 != 0)
{
int sum = 0;
const char chr_last_1 = name[0][strlen(name[0]) - 1];
const char chr_last_2 = name[1][strlen(name[1]) - 1];
for (int i = 0; i < n; i++)
{
if (chr_last_1 == sys_26[0][i])
{
sum += sys_26[1][i];
}
if (chr_last_2 == sys_26[0][i])
{
sum += sys_26[1][i];
}
}
if (sum % 2 == 0)
{
printf("Yes\n");
}
else
{
printf("No\n");
}
}
}