class Solution(object):

def findTheDifference(self, s, t):

"""

:type s: str

:type t: str

:rtype: str

"""

"""

# 100 pass - Simple problem of viewing the unmatched character iterating from a larger list

# Think of corner cases, when duplicate elements occurs, there occurs problem, solve it well before you think of the solution

# 100 pass - uses a separate list, try not using a separate list operation

s = list(s)

for ch in t:

if ch not in s:

return ch

else:

del s[s.index(ch)]

return -1

"""

"""

### Exor with same char negates itself so combining both the list and exoring each elements will result in the unique element

### Using EXOR

result = 0

for c in s+t:

result ^= ord(c)

return chr(result)

"""

### Nice logic - 100 pass

### Difference in the sum of hex all the characters

s_sum = sum([ord(i) for i in s])

t_sum = sum([ord(i) for i in t])

return chr(t_sum-s_sum)