#!/usr/bin/env python3
str1 = 'abcd1234'
str2 = 'bcde2345'
str3 = '7:69h5i>'
ord1 = (ord(c) for c in str1)
ord2 = (ord(c) for c in str2)
ord3 = (ord(c) for c in str3)
diffs = (x - y for x,y in zip(ord1, ord2))
result = (chr(x + y) for x,y in zip(diffs, ord3))
print(''.join(result))
IyEvdXNyL2Jpbi9lbnYgcHl0aG9uMwpzdHIxID0gJ2FiY2QxMjM0JwpzdHIyID0gJ2JjZGUyMzQ1JwpzdHIzID0gJzc6NjloNWk+JwoKb3JkMSA9IChvcmQoYykgZm9yIGMgaW4gc3RyMSkKb3JkMiA9IChvcmQoYykgZm9yIGMgaW4gc3RyMikKb3JkMyA9IChvcmQoYykgZm9yIGMgaW4gc3RyMykKCmRpZmZzID0gKHggLSB5IGZvciB4LHkgaW4gemlwKG9yZDEsIG9yZDIpKQoKcmVzdWx0ID0gKGNocih4ICsgeSkgZm9yIHgseSBpbiB6aXAoZGlmZnMsIG9yZDMpKQoKcHJpbnQoJycuam9pbihyZXN1bHQpKQ==