beecrowd | 2920
# Small Number

**Timelimit: 1**

By Anderson Franz, UNOCHAPECÓ Brazil

Carlos usually solves problems with large numbers, he is very good at math, but recently he came across a very difficult problem. He gained an **N** number from his mother and a **K** number from his father and his task is to make that number as small as possible, following the restrictions imposed by them. Remove **K** digits of the number **N** in order to make it as small as possible, not changing the order of the digits of the starting number **N**.

The input contains several test cases and ends with **EOF**, each line has an integer **K** and **N**, **N** <= 10^{100}, **K** < 100, **K**, **N** > 0.

The output is composed of a number representing the smallest number that can be formed, as described above.If you have leading zeros they should also be printed .

Input Sample | Output Sample |

23464656733331 4 7856756756 6 123456 4 0002504 3 |
2344533331 5556 12 0000 |