/* -*- coding: utf-8 -*-
 *
 * 2076.cc:  No.2076 Concon Substrings (ConVersion) - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 50000;
const int MAX_M = MAX_N / 3;
const int MAX_K = MAX_N / 3;

/* typedef */

/* global variables */

char s[MAX_N + 4];
int ls[MAX_M], dp[2][MAX_K + 1];

/* subroutines */

inline void setmax(int &a, int b) { if (a < b) a = b; }

/* main */

int main() {
  int n, a, b;
  scanf("%d%d%d%s", &n, &a, &b, s);
  int k = n / 3;
  
  int m = 0;
  for (int i = 0; i + 2 < n;) {
    while (i + 2 < n && s[i] != 'c') i++;
    if (i + 2 >= n) break;
    
    int j = i;
    while (i + 2 < n &&
	   s[i] == 'c' && s[i + 1] == 'o' && s[i + 2] == 'n') i += 3;
    int a = (i - j) / 3;
    if (a > 0) ls[m++] = a;
    else i++;
  }
  //for (int i = 0; i < m; i++) printf(" %d", ls[i]); putchar('\n');

  fill(dp[0], dp[0] + k + 1, -1);
  dp[0][0] = 0;
  int cur = 0, nxt = 1;

  for (int i = 0; i < k; i++) {
    fill(dp[nxt], dp[nxt] + k + 1, -1);
    for (int j = 0; j <= k; j++)
      if (dp[cur][j] >= 0) {
	for (int j1 = 0; j + j1 <= k && j1 * a <= ls[i]; j1++)
	  setmax(dp[nxt][j + j1], dp[cur][j] + (ls[i] - j1 * a) / b);
      }
    swap(cur, nxt);
  }

  int maxc = 0;
  for (int j = 1; j <= k; j++) {
    if (dp[cur][j] >= j) setmax(maxc, j * 2);
    else if (dp[cur][j] >= j - 1) setmax(maxc, j * 2 - 1);
  }

  printf("%d\n", maxc);

  return 0;
}