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.BigInteger;
import java.util.*;


public class GFG770 {
    static int mod1 = (int) (1e9 + 7);

    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        Scanner scan = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public Reader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public Reader(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String nextString() throws IOException {
            String str00 = scan.next();
            return str00;
        }

        public String readLine() throws IOException {
            byte[] buf = new byte[64]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n')
                    break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        String next() throws IOException {
            int c;
            for (c = read(); c <= 32; c = read());
            StringBuilder sb = new StringBuilder();
            for (; c > 32; c = read()) {
                sb.append((char) c);
            }
            return sb.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();

            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');

            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }

            if (neg)
                return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        public int[] nextArray(int n) throws IOException {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }
    }


    static int GCD(int a, int b) {
        BigInteger big1 = new BigInteger(String.valueOf(a));
        BigInteger big2 = new BigInteger(String.valueOf(b));
        big1 = big1.gcd(big2);
        return Integer.parseInt(big1.toString());
    }


    static boolean primeCheck(long num0) {
        boolean b1 = true;
        if (num0 == 1) {
            b1 = false;
        } else {
            int num01 = (int) (Math.sqrt(num0)) + 1;
            me1:
            for (int i = 2; i < num01; i++) {
                if (num0 % i == 0) {
                    b1 = false;
                    break me1;
                }
            }
        }
        return b1;
    }



    public static void main(String[] args) throws IOException {
        Reader r = new Reader();
        //PrintWriter writer=new PrintWriter(System.out);
        //Scanner r = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        OutputWriter770 out77 = new OutputWriter770(System.out);

        int num1=r.nextInt();
        int num2=r.nextInt();
        int num3=r.nextInt();
        String str1=r.next();
        int count0=0,count1=0;
        me1: for(int i=num1-1;i>-1;i--)
        {
            if(str1.charAt(i)=='1')
            {
                count1++;
            }
            count0++;
            if(count0==(num2))
            {
                break me1;
            }
        }
        if(str1.charAt(num1-1-num3)=='1')
        {
            count1--;
        }
        else
        {
            count1++;
        }
        out77.print(count1+"");
        r.close();
        out77.close();
    }
}

class OutputWriter770
{
    BufferedWriter writer;

    public OutputWriter770(OutputStream stream)
    {
        writer = new BufferedWriter(new OutputStreamWriter(stream));
    }
    public void print(int i) throws IOException
    {
        writer.write(i + "");
    }

    public void println(int i) throws IOException
    {
        writer.write(i + "\n");
    }

    public void print(String s) throws IOException
    {
        writer.write(s + "");
    }

    public void println(String s) throws IOException
    {
        writer.write(s + "\n");
    }

    public void print(char[] c) throws IOException
    {
        writer.write(c);
    }

    public void close() throws IOException
    {
        writer.flush();
        writer.close();
    }
}

class NodeInfo
{
    int data,dist;
    NodeInfo(int data,int dist)
    {
        this.data=data;
        this.dist=dist;
    }
}
