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 ≤ y < x < 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 ≤ y < x < n ≤ 2 ⋅ 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.

Examples

Input


11 5 2
11010100101


Output


1


Input


11 5 1
11010100101


Output


3

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.
import java.io.*;
import java.math.*;
import java.util.*;

public class Solution {
    /*
      InputReader class taken from https://gist.github.com/o-panda-o/32ce63499c05192827294eb529cc4fd0
      Which is publically available
    */
    static class InputReader {
    private boolean finished = false;

    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;

    public InputReader(InputStream stream) {
        this.stream = stream;
    }

    public int read() {
        if (numChars == -1) {
            throw new InputMismatchException();
        }
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0) {
                return -1;
            }
        }
        return buf[curChar++];
    }

    public int peek() {
        if (numChars == -1) {
            return -1;
        }
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                return -1;
            }
            if (numChars <= 0) {
                return -1;
            }
        }
        return buf[curChar];
    }

    public int nextInt() {
        int c = read();
        while (isSpaceChar(c)) {
            c = read();
        }
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do {
            if (c < '0' || c > '9') {
                throw new InputMismatchException();
            }
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public long nextLong() {
        int c = read();
        while (isSpaceChar(c)) {
            c = read();
        }
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do {
            if (c < '0' || c > '9') {
                throw new InputMismatchException();
            }
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public String nextString() {
        int c = read();
        while (isSpaceChar(c)) {
            c = read();
        }
        StringBuilder res = new StringBuilder();
        do {
            if (Character.isValidCodePoint(c)) {
                res.appendCodePoint(c);
            }
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }

    public boolean isSpaceChar(int c) {
        if (filter != null) {
            return filter.isSpaceChar(c);
        }
        return isWhitespace(c);
    }

    public static boolean isWhitespace(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    private String readLine0() {
        StringBuilder buf = new StringBuilder();
        int c = read();
        while (c != '\n' && c != -1) {
            if (c != '\r') {
                buf.appendCodePoint(c);
            }
            c = read();
        }
        return buf.toString();
    }

    public String readLine() {
        String s = readLine0();
        while (s.trim().length() == 0) {
            s = readLine0();
        }
        return s;
    }

    public String readLine(boolean ignoreEmptyLines) {
        if (ignoreEmptyLines) {
            return readLine();
        } else {
            return readLine0();
        }
    }

    public BigInteger readBigInteger() {
        try {
            return new BigInteger(nextString());
        } catch (NumberFormatException e) {
            throw new InputMismatchException();
        }
    }

    public char nextCharacter() {
        int c = read();
        while (isSpaceChar(c)) {
            c = read();
        }
        return (char) c;
    }

    public double nextDouble() {
        int c = read();
        while (isSpaceChar(c)) {
            c = read();
        }
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        double res = 0;
        while (!isSpaceChar(c) && c != '.') {
            if (c == 'e' || c == 'E') {
                return res * Math.pow(10, nextInt());
            }
            if (c < '0' || c > '9') {
                throw new InputMismatchException();
            }
            res *= 10;
            res += c - '0';
            c = read();
        }
        if (c == '.') {
            c = read();
            double m = 1;
            while (!isSpaceChar(c)) {
                if (c == 'e' || c == 'E') {
                    return res * Math.pow(10, nextInt());
                }
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                m /= 10;
                res += (c - '0') * m;
                c = read();
            }
        }
        return res * sgn;
    }

    public boolean isExhausted() {
        int value;
        while (isSpaceChar(value = peek()) && value != -1) {
            read();
        }
        return value == -1;
    }

    public String next() {
        return nextString();
    }

    public SpaceCharFilter getFilter() {
        return filter;
    }

    public void setFilter(SpaceCharFilter filter) {
        this.filter = filter;
    }

    public interface SpaceCharFilter {
        public boolean isSpaceChar(int ch);
    }
    public int[] nextIntArray(int n){
        int[] array=new int[n];
        for(int i=0;i<n;++i)array[i]=nextInt();
        return array;
    }
    public int[] nextSortedIntArray(int n){
        int array[]=nextIntArray(n);
        Arrays.sort(array);
        return array;
    }
    public int[] nextSumIntArray(int n){
        int[] array=new int[n];
        array[0]=nextInt();
        for(int i=1;i<n;++i)array[i]=array[i-1]+nextInt();
        return array;
    }
    public long[] nextLongArray(int n){
        long[] array=new long[n];
        for(int i=0;i<n;++i)array[i]=nextLong();
        return array;
    }
    public long[] nextSumLongArray(int n){
        long[] array=new long[n];
        array[0]=nextInt();
        for(int i=1;i<n;++i)array[i]=array[i-1]+nextInt();
        return array;
    }
    public long[] nextSortedLongArray(int n){
        long array[]=nextLongArray(n);
        Arrays.sort(array);
        return array;
    }
}
    static long mod = 1000000007L;
    public static void main(String[] args) {
        InputReader sc=new InputReader(System.in);
        PrintWriter out=new PrintWriter(new BufferedOutputStream(System.out), true);
        int n = sc.nextInt();
        int x = sc.nextInt();
        int y = sc.nextInt();
        String num = sc.next();
        int ans = 0;
        for(int i=n-x;i<n;i++){
            if(i!=n-y-1){
                if(num.charAt(i)=='1') ans++;
            }
            else {
                if(num.charAt(i)=='0') ans++;
            }
        }
        System.out.println(ans);
    }
    static class Pair implements Comparable<Pair> {
        int id, val;
        public Pair(int a, int b){
            id = a;
            val = b;
        }
        public boolean equals(Object o){
            if(o instanceof Pair){
                Pair p = (Pair)o;
                return val==p.val;
            }
            return false;
        }
        public int compareTo(Pair p){
            return val-p.val;
        }
    }
}