#include<bits/stdc++.h>
#define pb push_back
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
inline ll read(){
	ll x=0,c=getchar();
	while(c<'0'||c>'9')c=getchar();
	while(c>='0' && c<='9')x=x*10 + c-'0',c=getchar();
	return x;
}
const int N=2e5+3;
int n,r,b;
int B[N],R[N];
const int M=N*324;
int t[M],son[M][2],rt[M],tot;
#define mid ((l+r)>>1)
int cnt1,cnt2;
inline void update(int &x,int l,int r,int nx,int k){
	if(!x)t[x=++tot]=INT_MIN;t[x]=max(t[x],k);
	if(l==r)return ;
	if(nx<=mid)update(son[x][0],l,mid,nx,k);
	else update(son[x][1],mid+1,r,nx,k);
}
inline int query(int x,int l,int r,int nx){
	if(!x)return INT_MIN;
	if(nx<=l)return t[x];
	int res = query(son[x][1],mid+1,r,nx);
	if(nx<=mid)res = max(res,query(son[x][0],l,mid,nx));
	return res;
}
inline void add(int &x,int l,int r,int nx,int ny,int k){
	if(!x)x=++tot;
	update(rt[x],0,cnt2,ny,k);
	if(l==r)return ;
	if(nx<=mid)add(son[x][0],l,mid,nx,ny,k);
	else add(son[x][1],mid+1,r,nx,ny,k);
}
inline int qmax(int x,int l,int r,int nx,int ny){
	if(!x)return INT_MIN;
	if(nx<=l)return query(rt[x],0,cnt2,ny);
	int res = qmax(son[x][1],mid+1,r,nx,ny);
	if(nx<=mid)res = max(res,qmax(son[x][0],l,mid,nx,ny));
	return res;
}
int f[N],RT[N],t1[N],t2[N];
int main(){
	//freopen("data.in","r",stdin);
	n=read(),r=read(),b=read();int p=r+b;
	rep(i,1,n){
		int c=getchar();while(c!='B' && c!='W' && c!='R') c=getchar();
		B[i] = B[i-1] + (c=='B');R[i] = R[i-1] + (c=='R');
		t1[i] = R[i] -i/p*r,t2[i] = B[i] - i/p*b;
	}
	sort(t1,t1+n+1),cnt1=unique(t1,t1+n+1)-t1-1;
	sort(t2,t2+n+1),cnt2=unique(t2,t2+n+1)-t2-1;
	rep(i,0,n){
		int c = i%p;
		int x=lower_bound(t1,t1+cnt1+1,R[i]-i/p*r)-t1;
		int y=lower_bound(t2,t2+cnt2+1,B[i]-i/p*b)-t2;
		if(i>=p)f[i] = max(f[i-1],i/p + qmax(RT[c],0,cnt1,x,y));
		if(i<=n-p)add(RT[c],0,cnt1,x,y,f[i] - i/p);
	}
	cout<<f[n];
}