#include<bits/stdc++.h>
using namespace std;
#define md(a) a=(a%mod+mod)%mod
#define file(a) freopen(#a".in","r",stdin);freopen(#a".out","w",stdout)

bool ST;

const int N=200005,inf=1e9;
int n,lim[2],L,a[N][2],P,id[N][2],f[N];char s[N];
inline bool cmp(int x,int y){return a[x][P]-a[y][P]<1ll*lim[P]*(x-y)/L;}
struct Seg{int lc,rc,dat;}tree[N*100];int tot;
struct Mod
{
	int r,len[2],rt;vector<int>inc;
	void ady(int &v,int y,int d,int L,int R)
	{
		if(!v)v=++tot,tree[v].dat=-inf;tree[v].dat=max(tree[v].dat,d);if(L==R)return ;
		int mid=(L+R)>>1;if(y<=mid)ady(tree[v].lc,y,d,L,mid);else ady(tree[v].rc,y,d,mid+1,R);
	}
	int asy(int v,int l,int r,int L,int R)
	{
		if(!v)return -inf;if(l<=L&&R<=r)return tree[v].dat;int mid=(L+R)>>1,ans=-inf;
		if(l<=mid)ans=max(ans,asy(tree[v].lc,l,r,L,mid));if(r>mid)ans=max(ans,asy(tree[v].rc,l,r,mid+1,R));return ans;
	}
	void adx(int &v,int x,int y,int d,int L,int R)
	{
		if(!v)v=++tot;ady(tree[v].dat,y,d,1,len[1]);if(L==R)return ;
		int mid=(L+R)>>1;if(x<=mid)adx(tree[v].lc,x,y,d,L,mid);else adx(tree[v].rc,x,y,d,mid+1,R);
	}
	int asx(int v,int l,int r,int ly,int ry,int L,int R)
	{
		if(!v)return -inf;if(l<=L&&R<=r)return asy(tree[v].dat,ly,ry,1,len[1]);int mid=(L+R)>>1,ans=-inf;
		if(l<=mid)ans=max(ans,asx(tree[v].lc,l,r,ly,ry,L,mid));if(r>mid)ans=max(ans,asx(tree[v].rc,l,r,ly,ry,mid+1,R));return ans;
	}
	inline void ins(int i){adx(rt,id[i][0],id[i][1],f[i]-i/L,1,len[0]);}
	inline int qry(int i){return asx(rt,id[i][0],len[0],id[i][1],len[1],1,len[0])+i/L;}
	inline void Init(int _r)
	{
		// cout<<"init:"<<_r<<'\n';
		r=_r;int x=r,las;while(x<=n)inc.push_back(x),x+=L;
		P=0,sort(inc.begin(),inc.end(),cmp),las=-1;
		for(int x:inc){if(las==-1||cmp(las,x))len[P]++;id[x][P]=len[P],las=x;}
		P=1,sort(inc.begin(),inc.end(),cmp),las=-1;
		for(int x:inc){if(las==-1||cmp(las,x))len[P]++;id[x][P]=len[P],las=x;}
		// for(int i=r;i<=n;i+=L)cout<<i<<":"<<id[i][0]<<' '<<id[i][1]<<'\n';
	}
}T[N];

bool ED;

signed main()
{
	int time_st=clock();
	cerr<<(&ST-&ED)/1024.0/1024<<endl;ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>n>>lim[0]>>lim[1]>>(s+1),L=lim[0]+lim[1];
	for(int i=1;i<=n;i++)
	{
		a[i][0]=a[i-1][0],a[i][1]=a[i-1][1];
		if(s[i]=='R')a[i][0]++;else if(s[i]=='B')a[i][1]++;
	}
	for(int i=0;i<L;i++)T[i].Init(i);T[0].ins(0);
	for(int i=1;i<=n;i++)f[i]=f[i-1],f[i]=max(f[i],T[i%L].qry(i)),T[i%L].ins(i);cout<<f[n]<<'\n';
	cerr<<(clock()-time_st)/1e6<<endl;return 0;
}