#include<bits/stdc++.h>
using namespace std;
const int N=2e5+5,inf=2e9;
int n,r,b,sr[N],sb[N],rt[N];
string s;
int tot;
struct STree{int lc,rc,val;}t[N*800];
void pushup(int p)
{
	t[p].val=max((t[p].lc==0?-inf:t[t[p].lc].val),(t[p].rc==0?-inf:t[t[p].rc].val));
}
void change1(int &p,int l,int r,int x,int v)
{
	if(!p)tot++,p=tot,t[p].val=-inf;if(l==r)return t[p].val=max(t[p].val,v),void();int mid=l+r>>1;
	if(x<=mid)change1(t[p].lc,l,mid,x,v);else change1(t[p].rc,mid+1,r,x,v);pushup(p);
}
void change2(int &p,int l,int r,int x,int y,int v)
{
	if(!p)p=++tot;change1(t[p].val,-2*n,2*n,y,v);if(l==r)return ;int mid=l+r>>1;
	if(x<=mid)change2(t[p].lc,l,mid,x,y,v);else change2(t[p].rc,mid+1,r,x,y,v);
}
int ask1(int p,int l,int r,int al,int ar)
{
	// cout<<p<<" "<<l<<" ss "<<r<<" "<<al<<" "<<ar<<endl;
	if(!p)return -inf;
	if(al<=l && r<=ar)return t[p].val;int mid=l+r>>1,res=-inf;
	if(al<=mid)res=max(res,ask1(t[p].lc,l,mid,al,ar));if(mid<ar)res=max(res,ask1(t[p].rc,mid+1,r,al,ar));
	return res;
}
int ask2(int p,int l,int r,int ax,int bx,int ay,int by)
{
	// cout<<p<<" "<<t[p].val<<" "<<l<<" "<<r<<" "<<ax<<" "<<bx<<" "<<ay<<" "<<by<<endl;
	if(!p)return -inf;
	if(ax<=l && r<=bx)return ask1(t[p].val,-2*n,2*n,ay,by);int mid=l+r>>1,res=-inf;
	// cout<<mid<<endl;
	if(ax<=mid)res=max(res,ask2(t[p].lc,l,mid,ax,bx,ay,by));if(mid<bx)res=max(res,ask2(t[p].rc,mid+1,r,ax,bx,ay,by));
	return res;
}
int f[N];
int main()
{
	scanf("%d %d %d",&n,&r,&b);
	cin>>s,s=' '+s;
	for(int i=1;i<=n;i++)sr[i]=sr[i-1]+(s[i]=='R'),sb[i]=sb[i-1]+(s[i]=='B');
	change2(rt[0],-2*n,2*n,0,0,0);
	for(int i=1;i<=n;i++)
	{
		f[i]=f[i-1];
		f[i]=max(f[i],ask2(rt[i%(r+b)],-2*n,2*n,sr[i]-i/(r+b)*r,2*n,sb[i]-i/(r+b)*b,2*n)+i/(r+b));
		change2(rt[i%(r+b)],-2*n,2*n,sr[i]-i/(r+b)*r,sb[i]-i/(r+b)*b,f[i]-i/(r+b));
	}
	printf("%d\n",f[n]);
	return 0;
}