#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;
using ld = long double;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 2e5 + 5;
const int inf = 1e9 + 5;

#define lsb(p) (p & -p)
struct AIB {
   int fake = 0;
   map<int, int> nrm;
   vector<int> tree;
   AIB(): fake(0) {;}
   
   void upd(int p, int x) {
      if(!fake) {
         nrm[p];
         return;
      }
      p = nrm[p];
      while(p > 0) tree[p] = max(tree[p], x), p -= lsb(p);
      
      return;
   }
   int query(int p) {
      //cerr << "? " << p << '\n';
      if(!fake) { nrm[p]; return 0;}
      int sum = -inf;
      p = nrm[p];
      while(p < sz(tree)) sum = max(sum, tree[p]), p += lsb(p); 
      return sum;
   }
   
   void donefaking() {
      fake++;
      int cnt = 0;
      for(auto &[a, b] : nrm) b = ++cnt;
      tree.assign(cnt + 2, -inf);
      return;
   }
   
};

struct AIB2D {
   int fake = 0;
   
   vector<AIB> tree;
   map<int, int> nrm;
   
   void upd(int x, int y, int aggr) {
      if(!fake) { nrm[x]; return; }
      x = nrm[x];
      while(x > 0) tree[x].upd(y, aggr), x -= lsb(x);
      return;
   }
   int query(int x, int y) {
      if(!fake) { nrm[x]; return 0; }
      x = nrm[x];
      int sum = -inf;
      while(x < sz(tree)) sum = max(sum, tree[x].query(y)), x += lsb(x);
      return sum;
   }
   
   void donefaking() {
      fake++;
      if(fake == 1) {
         tree.assign(sz(nrm) + 2, AIB());
         int cnt = 0;
         for(auto &[a, b] : nrm) b = ++cnt;
      }
      if(fake == 2) {
         for(auto &x : tree) x.donefaking();
      }
      return;
   }
};

int red[nmax], blue[nmax], spr[nmax], spb[nmax];
int dp[nmax];

signed main() {
   cin.tie(0) -> sync_with_stdio(0);
   int n, r, b, K;
   cin >> n >> r >> b;
   K = r + b;
   
   string s;
   cin >> s;
   s = "$" + s;

   vector<AIB2D> states(K);
   
   
   for(int i = 1; i <= sz(s); i++) { 
      red[i] += (s[i] == 'R') + red[i - 1];
      blue[i] += (s[i] == 'B') + blue[i - 1];
   }
   
   for(int time = 0; time < 3; time++) {
      for(int i = 0; i < K; i++) {
         states[i % K].upd(0, 0, 0 - i / K);
         spr[i] = 0;
         spb[i] = 0;
      }
      for(int i = K; i < sz(s); i++) {
         spr[i] = spr[i - K] + red[i] - red[i - K] - r;
         spb[i] = spb[i - K] + blue[i] - blue[i - K] - b;
         //cerr << spr[i] << ' ' << spb[i] << '\t' << states[i % K].query(spr[i], spb[i]) 
         dp[i] = max(dp[i - 1], states[i % K].query(spr[i], spb[i]) + i / K);
         states[i % K].upd(spr[i], spb[i], dp[i] - i / K);
      }
      //cerr << '\n';
      for(auto &x : states) x.donefaking();
   }
   
   cout << dp[n] << '\n';
   
   
}

/**
      Ovaj podrum ima hladan sjaj\Iako je to bolje od gomile drugih
--
*/