#include<bits/stdc++.h>
using namespace std;

using int64 = long long;

const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;

const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;

template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for (int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for (T &in: v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for (auto &e: t) fill_v(e, v);
}

template< typename F >
struct FixPoint: F {
  explicit FixPoint(F &&f): F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

int main() {
  int N, A, B;
  cin >> N >> A >> B;
  string S;
  cin >> S;
  int pre = -inf;
  vector< int > vs;
  for(int i = 2; i < N; i++) {
    if(S[i - 2] == 'c' and S[i - 1] == 'o' and S[i] == 'n') {
      if(pre + 3 != i) {
        vs.emplace_back();
      }
      vs.back()++;
      pre = i;
    }
  }
  vector< int > dp1 {0};
  for(auto& p : vs) {
    vector< int > dp2(dp1.size() + p / A, -inf);
    for(int odd = 0; odd * A <= p; odd++) {
      int even = (p - odd * A) / B;
      for(int i = 0; i < (int) dp1.size(); i++) {
        chmax(dp2[i + odd], dp1[i] + even);
      }
    }
    dp1 = move(dp2);
  }
  int ret = 0;
  for(int i = 1; i < dp1.size(); i++) {
    if(dp1[i] >= i - 1) {
      chmax(ret, i + min(i, dp1[i]));
    }
  }
  cout << ret << endl;
}