#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, a, b; string s; cin >> n >> a >> b >> s;
  vector<int> segments;
  for (int i = 0; i + 3 <= s.length();) {
    if (s.substr(i, 3) != "con") {
      ++i;
      continue;
    }
    int segment = 1, j = i + 3;
    while (j + 3 <= s.length() && s.substr(j, 3) == "con") {
      ++segment;
      j += 3;
    }
    segments.emplace_back(segment);
    i = j;
  }
  const int m = n / a;
  vector<int> dp(m + 1, -INF);
  dp[0] = 0;
  for (const int segment : segments) {
    for (int i = m; i >= 0; --i) {
      if (dp[i] < 0) continue;
      for (int j = 1; j * a <= segment && i + j <= m; ++j) {
        chmax(dp[i + j], dp[i] + (segment - j * a) / b);
      }
      dp[i] += segment / b;
    }
  }
  int ans = 0;
  FOR(i, 1, m + 1) {
    if (dp[i] < 0) break;
    chmax(ans, min(i, dp[i] + 1) + min(dp[i], i));
  }
  cout << ans << '\n';
  return 0;
}