Score: 300 points
Mr. Infinity has a string S consisting of digits from 1 to 9. Each time the date changes, this string changes as follows:
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?
Input is given from Standard Input in the following format:
S K
Print the K-th character from the left in Mr. Infinity's string after 5 \times 10^{15} days.
1214 4
2
The string S changes as follows:
121412214444122221444444444444444412222222214444444444444444444444444444444444444444444444444444444444444444The first five characters in the string after 5 \times 10^{15} days is 12222. As K=4, we should print the fourth character, 2.
3 157
3
The initial string is 3. The string after 5 \times 10^{15} days consists only of 3.
299792458 9460730472580800
2