给定n 位正整数a，去掉其中任意k≤n 个数字后，剩下的数字按原次序排列组成一个新的正整数。对于给定的n位正整数a 和正整数k，设计一个算法找出剩下数字组成的新数最小的删数方案。

对于给定的正整数a，编程计算删去k个数字后得到的最小数。

,Given n-bit positive integer a, which removed any k ≤ n digits, the remaining number of the original order to form a new positive integer. For a given n-bit positive integer a and positive integer k, to design an algorithm to identify the composition of the remaining number of the smallest number of new programs to delete a few. For a given positive integer a, calculated by deleting the k-digit number after the minimum.