#include<bits/stdc++.h>
using namespace std;

const int maxn=2e5+5, maxt=1e8, maxt2=5e6+5, inf=1e8;
char s[maxn];

int tot, tot2, n;
int ls[maxt] ,rs[maxt], val[maxt];
int rt[maxn], rt2[maxt2], Ls[maxt2],Rs[maxt2];
int s1[maxn], s2[maxn], dp[maxn];

int ask2(int x,int L,int R,int l,int r) {
	if(!x) return -inf;
	if(L<=l&&r<=R) return val[x];
	int mid=l+r>>1, res=-inf;
	if(L<=mid) res=max(res,ask2(ls[x],L,R,l,mid));
	if(mid<R) res=max(res,ask2(rs[x],L,R,mid+1,r));
	return res;
}

int ask(int x,int L1,int R1,int L2,int R2,int l,int r) {
	if(!x) return -inf;
	if(L1<=l&&r<=R1) return ask2(rt2[x],L2,R2,-n,n);
	int mid=l+r>>1, res=-inf;
	if(L1<=mid) res=max(res,ask(Ls[x],L1,R1,L2,R2,l,mid));
	if(mid<R1) res=max(res,ask(Rs[x],L1,R1,L2,R2,mid+1,r));
	return res;
}

void add2(int& x,int p,int v,int l,int r) {
	if(!x) x=++tot2, val[x]=-inf;
	val[x]=max(val[x],v);
	if(l==r) return ;
	int mid=l+r>>1;
	if(p<=mid) add2(ls[x],p,v,l,mid);
	else add2(rs[x],p,v,mid+1,r);
	return ;
}

void add(int& x,int p1,int p2,int v,int l,int r) {
	if(!x) x=++tot;
	add2(rt2[x],p2,v,-n,n);
	if(l==r) return ;
	int mid=l+r>>1;
	if(p1<=mid) add(Ls[x],p1,p2,v,l,mid);
	else add(Rs[x],p1,p2,v,mid+1,r);
	return ;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	int r,b; cin>>n>>r>>b;
	for(int i=1;i<=n;i++) cin>>s[i];
	for(int i=1;i<=n;i++) {
		s1[i]=s1[i-1]+(s[i]=='B');
		s2[i]=s2[i-1]+(s[i]=='R');
	}
	dp[0]=0;
	add(rt[0],0,0,0,-n,n);
	for(int i=1;i<=n;i++) {
		dp[i]=max(dp[i-1],ask(rt[i%(r+b)],s1[i]-(i/(r+b))*b,n,s2[i]-(i/(r+b))*r,n,-n,n)+i/(r+b));
		add(rt[i%(r+b)],s1[i]-(i/(r+b))*b,s2[i]-(i/(r+b))*r,dp[i]-i/(r+b),-n,n);
	}
	cout<<dp[n]<<'\n';
	return 0;
}