#ifdef LOCAL
#include "stdafx.h"
#else
#include <bits/stdc++.h>
#define IL inline
#define LL long long
#define eb emplace_back
#define L(i, j, k) for (int i = (j); i <= (k); ++i)
#define R(i, j, k) for (int i = (j); i >= (k); --i)
using namespace std;

using vi = vector<int>;
#endif

constexpr int N = 2e5 + 9;
int n, m, a, b, c[N][2], P[N], Q[N];
char S[N];

int d[N << 5];
bool vis[N << 5];

vi g[N << 5];

int t;

struct BIT {
  int p[N], k;

  void bld (int sz) {
    k = sz;
    memset(p, -1, (k + 1) << 2);
  }

  void c (int x, int v) {
    for (; x <= k; x += x & -x) {
      int o = p[x];
      p[x] = ++t;
      g[t].eb(v);
      if (~o) {
        g[t].eb(o);
      }
    }
  }

  void q (int x, int v) {
    for (; x; x &= x - 1) {
      if (~p[x]) {
        g[v].eb(p[x]);
      }
    }
  }
} T;

int main () {
  ios::sync_with_stdio(0), cin.tie(0);
  cin >> n >> a >> b >> S;
  t = n;
  m = a + b;
  L (i, 0, n - 1) {
    if (S[i] == 'R') {
      ++c[i + 1][0];
    } else if (S[i] == 'B') {
      ++c[i + 1][1];
    }
  }
  L (i, 1, n) {
    L (j, 0, 1) {
      c[i][j] += c[i - 1][j];
    }
  }
  L (i, 1, n) {
    P[i] = i < m ? 0 : P[i - m] + c[i][0] - c[i - m][0] - a;
    Q[i] = i < m ? 0 : Q[i - m] + c[i][1] - c[i - m][1] - b;
  }
  L (i, 0, m - 1) {
    vector<int> p, q;
    for (int j = i; j <= n; j += m) {
      p.eb(j);
      q.eb(Q[j]);
    }
    sort(q.begin(), q.end());
    q.erase(unique(q.begin(), q.end()), q.end());
    int k = q.size();
    T.bld(k);
    sort(p.begin(), p.end(), [] (int x, int y) {
      return P[x] ^ P[y] ? P[x] < P[y] : Q[x] ^ Q[y] ? Q[x] < Q[y] : x > y;
    });
    for (int x : p) {
      int y = lower_bound(q.begin(), q.end(), Q[x]) - q.begin() + 1;
      T.q(y, x);
      T.c(y, x);
    }
  }

  deque<int> q;
  memset(d, 0x3f, (t + 1) << 2);
  d[0] = 0;
  q.push_back(0);
  while (!q.empty()) {
    int u = q.front();
    q.pop_front();
    if (vis[u]) {
      continue;
    }
    vis[u] = true;
    for (int v : g[u]) {
      if (d[v] > d[u]) {
        d[v] = d[u];
        q.push_front(v);
      }
    }
    if (u + 1 <= n && d[u + 1] > d[u] + 1) {
      d[u + 1] = d[u] + 1;
      q.push_back(u + 1);
    }
  }

  // cout << t << '\n';
  // L (i, 0, t) {
  //   for (int j : g[i]) {
  //     cout << '(' << i << ", " << j << ")\n";
  //   }
  // }

  // cout << d[n] << '\n';

  cout << (n - d[n]) / m << '\n';
}
// I love WHQ!