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toinfinity Batch , stdin/stdout

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toinfinity.html

toinfinity

Problem Statement

Mr. Infinity has a string S consisting of digits from 1 to 9. Each time the date changes, this string changes as follows:

  • Each occurrence of 2 in S is replaced with 22. Similarly, each 3 becomes 333, 4 becomes 4444, 5 becomes 55555, 6 becomes 666666, 7 becomes 7777777, 8 becomes 88888888 and 9 becomes 999999999. 1 remains as 1.

For example, if S is 1324, it becomes 1333224444 the next day, and it becomes 133333333322224444444444444444 the day after next. You are interested in what the string looks like after 5 × 1015 days. What is the K-th character from the left in the string after 5 × 1015 days?

Constraints

  • S is a string of length between 1 and 100 (inclusive).
  • K is an integer between 1 and 1018 (inclusive).
  • The length of the string after 5 × 1015 days is at least K.

Input

Input is given from Standard Input in the following format:

S
K

Output

Print the K-th character from the left in Mr. Infinity's string after 5 × 1015 days.

Sample Input 1

1214
4

Sample Output 1

2

The string S changes as follows:

  • Now: 1214
  • After one day: 12214444
  • After two days: 1222214444444444444444
  • After three days: 12222222214444444444444444444444444444444444444444444444444444444444444444

The first five characters in the string after 5 × 1015 days is 12222. As K=4, we should print the fourth character, 2.

Sample Input 2

3
157

Sample Output 2

3

The initial string is 3. The string after 5 × 1015 days consists only of 3.

Sample Input 3

299792458
9460730472580800

Sample Output 3

2

Tags

Subtasks and Limits

Subtask Score #TC Time Memory Scoring
1100161s128MBMinimum
2031s128MBMinimum

Judge Compile Command

g++-8 ans.cpp -o toinfinity -Wall -Wshadow -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512

Accepted Submissions

subIDUserTimeMax Time

Past Submissions

subIDUserTimeScore
mrJudge 09.05.20
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