Cryptogram Cracking Club | 프로그래밍의 벗 PivotOJ
PivotOJ

Cryptogram Cracking Club

시간 제한: 2000ms메모리 제한: 2048MB출처: CCC 2025 SeniorBOJ 34467

문제

Cyrene, the captain of the Cryptogram Cracking Club (CCC), came across a concerningly long cipher. Conveniently, this cipher is composed of lower-case characters (a-z). Comfortingly, the cipher is composed of a pattern that repeats infinitely.

Cyrene wishes to locate the cc-th character of the cipher. To make your job easier, the CCC members have extracted the repeated pattern and compressed it using the Run-Length Encoding (RLE) algorithm, which replaces consecutive repeated characters with a single occurrence of the character followed by a count of how many times it was repeated. For example, for the pattern aaaabccdddd, the RLE algorithm outputs a4b1c2d4.

You are given the output of the RLE algorithm for a certain pattern. Can you determine the cc-th character of the long cipher that is formed by repeating this pattern infinitely?

입력

The first line of input will consist of a string SS, representing a pattern produced by the RLE algorithm. The length of SS will be at least 22 and at most 21052 \cdot 10^5. Additionally, all numbers appearing in SS are between 11 and 101210^{12}.

The next line of input contains a single integer cc (0 ≤ c ≤ 10^{12}), representing the index of the character you wish to locate, starting from index 0$.

출력

Output the cc-th character of the long cipher.

예제

예제 1

입력
r2d2
8
출력
r

예제 2

입력
a4b1c2d10
100
출력
d
코드를 제출하려면 로그인하세요.