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.util.*;
import java.io.*;  
public class Main 
{
    PrintWriter out;
    FastReader sc;
    long[] m1= {(long)(1e9+7),998244353};
    long mod=m1[1];
    long maxlong=Long.MAX_VALUE;
    long minlong=Long.MIN_VALUE;
    StringBuilder sb;
    /******************************************************************************************
     *****************************************************************************************/
	public void sol(){
		int n=ni(),x=ni(),y=ni();
		char[] s=rl();
		StringBuilder a=new StringBuilder(),b=new StringBuilder();
		
		for(int i=0;i<y;i++)a.append("0");
		a.append("1");
		for(int i=y+1;i<x;i++)a.append("0");
		a.reverse();
		for(int i=0;i<x;i++)b.append(s[n-i-1]);
		b.reverse();
		int ans=0;
		for(int i=0;i<x;i++) {
			if(a.charAt(i)!=b.charAt(i))ans++;
		}pl(ans);
	}
    public static void main(String[] args) 
	{ 
	    Main g=new Main();
		g.out=new PrintWriter(System.out);
		g.sc=new FastReader();
		int t=1;
// 		t=g.ni();
		while(t-->0)
		g.sol();
		g.out.flush();
	}
	
	/****************************************************************************************
     *****************************************************************************************/
	static class FastReader 
	{ 
		BufferedReader br; 
		StringTokenizer st; 
 
		public FastReader() 
		{ 
			br = new BufferedReader(new
					InputStreamReader(System.in)); 
		} 
 
		String next() 
		{ 
			while (st == null || !st.hasMoreElements()) 
			{ 
				try
				{ 
					st = new StringTokenizer(br.readLine()); 
				} 
				catch (IOException e) 
				{ 
					e.printStackTrace(); 
				} 
			} 
			return st.nextToken(); 
		} 
 
		int nextInt() 
		{ 
			return Integer.parseInt(next()); 
		} 
 
		long nextLong() 
		{ 
			return Long.parseLong(next()); 
		} 
 
		double nextDouble() 
		{ 
			return Double.parseDouble(next()); 
		} 
 
		String nextLine() 
		{ 
			String str = ""; 
			try
			{ 
				str = br.readLine(); 
			} 
			catch (IOException e) 
			{ 
				e.printStackTrace(); 
			} 
			return str; 
		} 
	} public int ni(){
	      return sc.nextInt();
	}public long nl(){
	      return sc.nextLong();
	}public double nd(){
	      return sc.nextDouble();
	}public char[] rl(){
	      return sc.nextLine().toCharArray();
	}public String rl1(){
	      return sc.nextLine();
	}
	public void pl(Object s){
	      out.println(s);
	}public void ex(){
	      out.println();
	}
	public void pr(Object s){
	      out.print(s);
	}public String next(){
	      return sc.next();
	}public long abs(long x){
	      return Math.abs(x);
	}
	public int abs(int x){
	      return Math.abs(x);
	}
	public double abs(double x){
	      return Math.abs(x);
	}public long min(long x,long y){
            return (long)Math.min(x,y);
      }
      public int min(int x,int y){
            return (int)Math.min(x,y);
      }
      public double min(double x,double y){
            return Math.min(x,y);
      }public long gcd(long a, long b) {
		if (a == 0)
			return b;
		return gcd(b % a, a);
	}public long lcm(long a, long b) {
            return (a / gcd(a, b)) * b;
      }
       void sort1(int[] a) {
		ArrayList<Integer> l = new ArrayList<>();
		for (int i : a) {
			l.add(i);
		}
		Collections.sort(l,Collections.reverseOrder());
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}
	 void sort(int[] a) {
		ArrayList<Integer> l = new ArrayList<>();
		for (int i : a) {
			l.add(i);
		}
		Collections.sort(l);
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}void sort(long[] a) {
		ArrayList<Long> l = new ArrayList<>();
		for (long i : a) {
			l.add(i);
		}
		Collections.sort(l);
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}void sort1(long[] a) {
		ArrayList<Long> l = new ArrayList<>();
		for (long i : a) {
			l.add(i);
		}
		Collections.sort(l,Collections.reverseOrder());
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}
	void sort(double[] a) {
		ArrayList<Double> l = new ArrayList<>();
		for (double i : a) {
			l.add(i);
		}
		Collections.sort(l);
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}long pow(long a,long b){
          if(b==0){
                return 1;
          }long p=pow(a,b/2);
          if(b%2==0) return (p*p)%mod;
          else return (((p*p)%mod)*a)%mod;
    }
	
	int  swap(int a,int b){
	      return a;
	}long  swap(long a,long b){
	      return a;
	}double  swap(double a,double b){
	      return a;
	}
	boolean isPowerOfTwo (int x) 
      { 
            return x!=0 && ((x&(x-1)) == 0);     
      }boolean isPowerOfTwo (long x) 
      { 
            return x!=0 && ((x&(x-1)) == 0);     
      }public long max(long x,long y){
            return (long)Math.max(x,y);
      }
      public int max(int x,int y){
            return (int)Math.max(x,y);
      }
      public double max(double x,double y){
            return Math.max(x,y);
      }long sqrt(long x){
            return (long)Math.sqrt(x);
      }int sqrt(int x){
            return (int)Math.sqrt(x);
      }void input(int[] ar,int n){
            for(int i=0;i<n;i++)ar[i]=ni();
      }void input(long[] ar,int n){
            for(int i=0;i<n;i++)ar[i]=nl();
      }void fill(int[] ar,int k){
            Arrays.fill(ar,k);
      }void yes(){
            pl("YES");
      }void no(){
            pl("NO");
      }
      long c2(long n) {
    	  return (n*(n-1))/2;
      }
    long[] sieve(int n) 
    {
          long[] k=new long[n+1];
          boolean[] pr=new boolean[n+1];
          for(int i=1;i<=n;i++){
                k[i]=i;
                pr[i]=true;
          }for(int i=2;i<=n;i++){
                if(pr[i]){
                      for(int j=i+i;j<=n;j+=i){
                            pr[j]=false;
                            if(k[j]==j){
                                  k[j]=i;
                            }
                      }
                }
          }return k;
    }
    int strSmall(int[] arr, int target)  
    {  
        int start = 0, end = arr.length-1;  
        int ans = -1;  
        while (start <= end) {  
            int mid = (start + end) / 2;   
            if (arr[mid] >= target) {  
                end = mid - 1;  
            }   
            else {  
                ans = mid;  
                start = mid + 1;  
            }  
        }  
        return ans;  
    } int strSmall(ArrayList<Integer> arr, int target)  
    {  
        int start = 0, end = arr.size()-1;  
        int ans = -1;  
        while (start <= end) {  
            int mid = (start + end) / 2;   
            if (arr.get(mid) > target) {  
                start = mid + 1; 
                ans=start;
            }   
            else {
                end = mid - 1;  
            }  
        }  
        return ans;  
    }long mMultiplication(long a,long b) 
    { 
        long res = 0;    
        a %= mod; 
  
        while (b > 0)  
        {  
            if ((b & 1) > 0)  
            { 
                res = (res + a) % mod; 
            }  
            a = (2 * a) % mod; 
  
            b >>= 1;  
        } 
        return res; 
    }long nCr(int n, int r ,int p)
    {
 
          if (n<r) 
              return 0;
        if (r == 0)
            return 1;
            long[] fac = new long[n + 1];
        fac[0] = 1;
 
        for (int i = 1; i <= n; i++)
            fac[i] = fac[i - 1] * i %p;
        return (fac[n] * modInverse(fac[r], p)
                % p * modInverse(fac[n - r], p)
                % p)
            % p;
    }long power(long x, long y, long p)
    {
        long res = 1;
        x = x % p;
 
        while (y > 0) {
            if (y % 2 == 1)
                res = (res * x) % p;
            y = y >> 1; 
            x = (x * x) % p;
        }
 
        return res;
    }long modInverse(long n, long p)
    {
        return power(n, p - 2, p);
    }
    
    int[][] floydWarshall(int graph[][],int INF,int V)
    {
        int dist[][] = new int[V][V];
        int i, j, k;
        for (i = 0; i < V; i++)
            for (j = 0; j < V; j++)
                dist[i][j] = graph[i][j];
        for (k = 0; k < V; k++)
        {
            for (i = 0; i < V; i++)
            {
                for (j = 0; j < V; j++)
                {
                    if (dist[i][k] + dist[k][j] < dist[i][j])
                        dist[i][j] = dist[i][k] + dist[k][j];
                }
            }
        }return dist;
    }
    class minque {
		Deque<Long> q;
		minque(){
			q=new ArrayDeque<Long>();
		}public void add(long p){
			while(!q.isEmpty()&&q.peekLast()>p)q.pollLast();
			q.addLast(p);
		}public void remove(long p) {
			if(!q.isEmpty()&&q.getFirst()==p)q.removeFirst();
		}public long min() {
			return q.getFirst();
		}
	}
      public static class Pair implements Comparable<Pair> {
		long x;
		long y;
 
		public Pair(long x, long y) {
			this.x = x;
			this.y = y;
		}
		public Pair() {
			// TODO Auto-generated constructor stub
		}
		public int compareTo(Pair other) {
			if (this.x == other.x) {
				return Long.compare(other.y, this.y);
			}
			return Long.compare(other.x, this.x);
		}
      }int find(subset[] subsets, int i)
      {
          if (subsets[i].parent != i)
              subsets[i].parent
                  = find(subsets, subsets[i].parent);
          return subsets[i].parent;
      }void Union(subset[] subsets, int x, int y)
      {
          int xroot = find(subsets, x);
          int yroot = find(subsets, y);
   
          if (subsets[xroot].rank < subsets[yroot].rank) {
          	subsets[xroot].parent = yroot;
          }
          else if (subsets[yroot].rank < subsets[xroot].rank) {
          	subsets[yroot].parent = xroot;
          }
          else {
              subsets[xroot].parent = yroot;
              subsets[yroot].rank++;
          }
      }class subset
      {
          int parent;
          int rank;
      }
	 
} 