Cipher Cadence Outlier

A listening post has recorded n encoded transmissions. Every transmission is a string of exactly m lowercase English letters, and all n transmissions share the same length m. For a transmission s, define its cadence as the sequence of m-1 values where the i-th value is the character code of s[i+1] minus the character code of s[i] (treating 'a' through 'z' as consecutive codes, so the sign and size of each step is what matters). It is guaranteed that all n transmissions share exactly the same cadence except for exactly one transmission, whose cadence differs from that common cadence in at least one position. Find and report that one transmission.

Input format

• Line 1: a single integer n.
• Each of the next n lines contains one transmission: a string of exactly m lowercase English letters. All n transmissions have the same length m.

Output format

Print the one transmission whose cadence differs from the cadence shared by all of the others.

Constraints

• 3 <= n <= 100
• 2 <= m <= 20
• Every string consists only of lowercase English letters, and all n strings have the same length m.
• Exactly one string has a cadence different from the common cadence shared by every other string.

3
adc
wzy
abc

abc

4
aaa
bob
ccc
ddd

bob