def birthday(s, d, m):# Write your code herecount = 0for i in range(len(s) + 1 - m):if (sum(s[i:i+m]) == d): count+=1return(count)
def strings_xor(s, t):res = ""for i in range(len(s)):if s[i] == t[i]:res += '0';else:res += '1';return ress = input()t = input()print(strings_xor(s, t))