class Solution:
def freqAlphabets(self, s: str) -> str:
res,i='',len(s)-1
while i>=0:
if s[i]=='#':
res+=chr(int(s[i-2:i])+96)
i-=3
else:
res+=chr(int(s[i])+96)
i-=1
return res[::-1]