Problem:
﻿Score: 300 points

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 \times 10^{15} days. What is the K-th character from the left in the string after 5 \times 10^{15} days?

Constraints

S is a string of length between 1 and 100 (inclusive).

K is an integer between 1 and 10^{18} (inclusive).

The length of the string after 5 \times 10^{15} 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 \times 10^{15} 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 \times 10^{15} 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 \times 10^{15} days consists only of 3.

Sample Input 3

299792458
9460730472580800

Sample Output 3

2

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
// define('DEBUG', true);
define('DEBUG', false);

fscanf(STDIN, "%s", $S);
fscanf(STDIN, "%d", $K);

$array = array();
$other = "";

$pos = PHP_INT_MAX;
for ($i = 2; $i <= 9; $i++) {
	$array[$i] = strpos($S, strval($i));
	// echo $i . " - " . $array[$i] . PHP_EOL;
	if ($array[$i] !== false && $pos > $array[$i]) {
		$other = $i;
		$pos = $array[$i];
	}
}
// echo "other: " . $other . PHP_EOL;
if ($other == "") {
	$len1 = strlen($S);
} else {
	$len1 = min($array);
}
if ($K <= $len1) {
	echo "1";
} else {
	echo $other;
}