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

#define rep(i,l,r) for(int i=(l);i<=(r);i++)
#define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define mset(s,t) memset(s,t,sizeof(s))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define SZ(x) ((int)x.size())
#define pb push_back
#define eb emplace_back
#define fir first
#define sec second

template<class T1,class T2>bool ckmax(T1 &a,T2 b){if(a<b)return a=b,1;else return 0;}
template<class T1,class T2>bool ckmin(T1 &a,T2 b){if(a>b)return a=b,1;else return 0;}

inline int read(){
	int x=0,f=0;char ch=getchar();
	while(!isdigit(ch))f|=ch=='-',ch=getchar();
	while(isdigit(ch))x=10*x+ch-'0',ch=getchar();
	return f?-x:x;
}
template<typename T>void print(T x){
	if(x<0)putchar('-'),x=-x;
	if(x>=10)print(x/10);
	putchar(x%10+'0');
}
template<typename T>void print(T x,char ch){
	print(x),putchar(ch);
}

const int N=200005;
const int M=50000005;
const int inf=2e9;

char a[N];
int preR[N],preB[N],n,R,B;

struct node{
	int pos1,pos2,id;
}b[N],c[N];
int dp[N];

int mx[M],ls[M],rs[M],tot,root[N];
inline int newnode(){
	int u=++tot;
	ls[u]=rs[u]=0,mx[u]=-inf;
	return u;
}
inline void pushup(int u){
	mx[u]=max(mx[ls[u]],mx[rs[u]]);
}
void ins(int &u,int l,int r,int pos,int dlt){
	if(!u)u=newnode();
	if(l==r){ckmax(mx[u],dlt);return;}
	int mid=l+r>>1;
	if(pos<=mid)ins(ls[u],l,mid,pos,dlt);
	else ins(rs[u],mid+1,r,pos,dlt);
	pushup(u);
}
int qry(int u,int l,int r,int pos){
	if(!u)return -inf;
	if(pos<=l)return mx[u];
	int mid=l+r>>1,ret=qry(rs[u],mid+1,r,pos);
	if(pos<=mid)ckmax(ret,qry(ls[u],l,mid,pos));
	return ret;
}

void cdq(int l,int r){
	if(l==r){
		assert(b[l].id==l);
		if(l)ckmax(dp[l],dp[l-1]);
		// printf("dp[%d]=%d\n",l,dp[l]);
		return;
	}
	int mid=l+r>>1;
	cdq(l,mid);
	rep(i,mid+1,r)c[i]=b[i];
	sort(c+mid+1,c+r+1,[&](node x,node y){
		return x.pos1>y.pos1;
	});
	for(int i=l,j=mid+1;j<=r;j++){
		while(i<=mid&&b[i].pos1>=c[j].pos1){
			ins(root[b[i].id%(R+B)],-n,n,b[i].pos2,dp[b[i].id]-b[i].id/(R+B));
			i++;
		}
		ckmax(dp[c[j].id],qry(root[c[j].id%(R+B)],-n,n,c[j].pos2)+c[j].id/(R+B));
	}
	for(int i=l;i<=mid;i++)root[i%(R+B)]=0;
	while(tot)ls[tot]=rs[tot]=0,mx[tot]=-inf,tot--;
	cdq(mid+1,r);
	int x=l,y=mid+1,z=l;
	while(x<=mid&&y<=r){
		if(b[x].pos1>=b[y].pos1)c[z++]=b[x++];
		else c[z++]=b[y++];
	}
	while(x<=mid)c[z++]=b[x++];
	while(y<=r)c[z++]=b[y++];
	rep(i,l,r)b[i]=c[i];
}

int main(){
	mx[0]=-inf;
	scanf("%d%d%d",&n,&R,&B);
	scanf("%s",a+1);
	rep(i,1,n){
		preR[i]=preR[i-1],preB[i]=preB[i-1];
		if(a[i]=='R')preR[i]++;
		if(a[i]=='B')preB[i]++;
	}
	rep(i,1,n){
		b[i]={preR[i]-1ll*i*R/(R+B),preB[i]-1ll*i*B/(R+B),i};
	}
	cdq(0,n);
	print(dp[n],'\n');
	return 0;
}

/*
41 2 2
BRRRBRRRBBBBRRRBBRRRRRRRBBRRRBBBBRRRBRRRB
*/