#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, A, B;
  cin >> N >> A >> B;
  string S;
  cin >> S;
  vector<int> C(1, 0);
  for (int i = 0; i <= N - 3; i++){
    if (S.substr(i, 3) == "con"){
      C.back()++;
      i += 2;
    } else if (C.back() != 0){
      C.push_back(0);
    }
  }
  if (C.back() == 0){
    C.pop_back();
  }
  int cnt = C.size();
  vector<int> dp(1, 0);
  int N1 = 0;
  for (int i = 0; i < cnt; i++){
    int N2 = C[i] / A;
    for (int j = 0; j < N2; j++){
      dp.push_back(0);
    }
    for (int j = N1; j >= 0; j--){
      for (int k = N2; k >= 0; k--){
        dp[j + k] = max(dp[j + k], dp[j] + (C[i] - A * k) / B);
      }
    }
    N1 += N2;
  }
  int ans = 0;
  for (int i = 0; i < N1 + 1; i++){
    if (dp[i] >= i - 1){
      ans = max(ans, i);
    }
  }
  cout << ans << endl;
}