619 B | 619 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
while 1:
s = input()
if s == "#":
break
a, b, c = s.split()
ans = ""
for i in range(len(a)):
k = ord(b[i]) - ord(a[i])
d = chr(((ord(c[i]) - 97 + k + 26) % 26) + 97)
ans += d
p(a, b, c, ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()