After the cowardly attack of a hacker on the server of bank MoneyForNothing, its manager has realized that he has to change the numbers of all existing accounts, due to security reasons. Obviously, the modification has to be done very quickly, and that is why the manager decides that each account number n is to be replaced by the largest number that can be obtained from n by deleting exactly k digits, however maintaining the initial order of digits.

Being given integers n and k, written in base 10, determine the largest number that can be obtained from n by deleting exactly k digits, keeping the initial order of the digits.

Input file conturi.in contains on the first line the number k, and on the second line the number n.

Output file conturi.out will contain a single line with the requested number.

Constraints

• Non-zero positive integer n has no more than 1000 digits.
• Non-negative integer k is strictly smaller than the number of digits of n.