题目描述
Champernown constant is an irrational number represented in decimal by "0." followed by concatenation of all positive integers in the increasing order. The first few digits of this constant are: 0.123456789101112...
Your task is to write a program that outputs the K digits of Chapnernown constant starting at the N-th place for given two natural numbers K and N.
Input
The input has multiple lines. Each line has two positive integers N and K (N ≤ 109, K ≤ 100) separated by a space.
The end of input is indicated by a line with two zeros. This line should not be processed.
Output
For each line, output a line that contains the K digits.
Example
Input
4 5
6 7
0 0
Output
45678
6789101
输入格式
见题面
输出格式
见题面
样例输入
4 5
6 7
0 0
样例输出
45678
6789101