Codeforces Round 293 (Div. 2)
A
Vitaly and Strings
Codeforces
1600
原题
←B →
翻译中…

Vitaly is a diligent student who never missed a lesson in his five years of studying in the university. He always does his homework on time and passes his exams in time.

翻译中…

During the last lesson the teacher has provided two strings $*s*$ and $*t*$ to Vitaly. The strings have the same length, they consist of lowercase English letters, string $*s*$ is lexicographically smaller than string $*t*$. Vitaly wondered if there is such string that is lexicographically larger than string $*s*$ and at the same is lexicographically smaller than string $*t*$. This string should also consist of lowercase English letters and have the length equal to the lengths of strings $*s*$ and $*t*$.

翻译中…

Let's help Vitaly solve this easy problem!

翻译中…

Input

翻译中…

The first line contains string $*s*$ ($1 ≤ |*s*| ≤ 100$), consisting of lowercase English letters. Here, $|*s*|$ denotes the length of the string.

翻译中…

The second line contains string $*t*$ ($|*t*| = |*s*|$), consisting of lowercase English letters.

翻译中…

It is guaranteed that the lengths of strings $*s*$ and $*t*$ are the same and string $*s*$ is lexicographically less than string $*t*$.

翻译中…

Output

翻译中…

If the string that meets the given requirements doesn't exist, print a single string "No such string" (without the quotes).

翻译中…

If such string exists, print it. If there are multiple valid strings, you may print any of them.

翻译中…

Note

翻译中…

String $*s* = *s*_{1}*s*_{2}... *s*_{*n*}$ is said to be lexicographically smaller than $*t* = *t*_{1}*t*_{2}... *t*_{*n*}$, if there exists such $*i*$, that $*s*_{1} = *t*_{1}, *s*_{2} = *t*_{2}, ... *s*_{*i* - 1} = *t*_{*i* - 1}, *s*_{*i*} < *t*_{*i*}$.

翻译中…

样例

Input #1
a
c
Output #1
b
InputCopy OutputCopy
Input #2
aaa
zzz
Output #2
kkk
InputCopy OutputCopy
Input #3
abcdefg
abcdefh
Output #3
No such string
InputCopy OutputCopy
题目信息
题号
518A
时间限制
1 s
内存限制
256 MB
标签
构造
字符串

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