You are given a huge decimal number consisting of $$$n$$$ digits. It is guaranteed that this number has no leading zeros. Each digit of this number is either 0 or 1.

You may perform several (possibly zero) operations with this number. During each operation you are allowed to change any digit of your number; you may change 0 to 1 or 1 to 0. It is possible that after some operation you can obtain a number with leading zeroes, but it does not matter for this problem.

You are also given two integers $$$0 \le y \lt x \lt n$$$. Your task is to calculate the minimum number of operations you should perform to obtain the number that has remainder $$$10^y$$$ modulo $$$10^x$$$. In other words, the obtained number should have remainder $$$10^y$$$ when divided by $$$10^x$$$.

Input

The first line of the input contains three integers $$$n, x, y$$$ ($$$0 \le y \lt x \lt n \le 2 \cdot 10^5$$$) — the length of the number and the integers $$$x$$$ and $$$y$$$, respectively.

The second line of the input contains one decimal number consisting of $$$n$$$ digits, each digit of this number is either 0 or 1. It is guaranteed that the first digit of the number is 1.

Output

Print one integer — the minimum number of operations you should perform to obtain the number having remainder $$$10^y$$$ modulo $$$10^x$$$. In other words, the obtained number should have remainder $$$10^y$$$ when divided by $$$10^x$$$.

Note

In the first example the number will be $$$11010100100$$$ after performing one operation. It has remainder $$$100$$$ modulo $$$100000$$$.

In the second example the number will be $$$11010100010$$$ after performing three operations. It has remainder $$$10$$$ modulo $$$100000$$$.

Remainder

Examples