import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    static int[][] dp;
    static ArrayList<Integer> values = new ArrayList<>();
    static int a;
    static int b;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        a = sc.nextInt();
        b = sc.nextInt();
        char[] inputs = sc.next().toCharArray();
        int count = 0;
        int max = 0;
        for (int i = 0; i + 2 < n; i++) {
            if (inputs[i] == 'c' && inputs[i + 1] == 'o' && inputs[i + 2] == 'n') {
                count++;
                i += 2;
            } else {
                if (count / a > 0 || count / b > 0) {
                    values.add(count);
                }
                count = 0;
            }
        }
        if (count / a > 0 || count / b > 0) {
            values.add(count);
        }
        dp = new int[values.size()][];
        int sum = 0;
        for (int i = 0; i < values.size(); i++) {
            sum += values.get(i) / a;
            dp[i] = new int[sum + 1];
            Arrays.fill(dp[i], -1);
        }
        int ans = 0;
        for (int i = sum; i >= 0; i--) {
            int x = dfw(values.size() - 1, i);
            int current = Math.min(i, x) * 2;
            if (i > x) {
                current++;
            }
            ans = Math.max(ans, current);
        }
        System.out.println(ans);
    }
    
    static int dfw(int idx, int v) {
        if (idx < 0) {
            if (v == 0) {
                return 0;
            } else {
                return Integer.MIN_VALUE;
            }
        }
        if (v >= dp[idx].length) {
            return Integer.MIN_VALUE;
        }
        if (dp[idx][v] < 0) {
            dp[idx][v] = Integer.MIN_VALUE;
            int x = values.get(idx);
            for (int i = 0; i * a <= x && i <= v; i++) {
                dp[idx][v] = Math.max(dp[idx][v], dfw(idx - 1, v - i) + (x - i * a) / b);
            }
        }
        return dp[idx][v];
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}