//Man always remember love because of romance only!
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
    int n=0,w=0; char s=0;
    while(!isdigit(s)) {w|=s=='-';s=getchar();}
    while(isdigit(s)) n=(n<<3)+(n<<1)+(s^48),s=getchar();
    return w?-n:n;
}
inline void write(int x){
	if(x<0) putchar('-'),x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}
int n,r,b;
int tr[200010];
inline int lowbit(int x){
	return x&(-x);
}
void update(int x,int k){
	while(x<=n+1){
		tr[x]=max(tr[x],k);
		x+=lowbit(x);
	}
}
int query(int x){
	int res=-1e9;
	while(x){
		res=max(res,tr[x]);
		x-=lowbit(x);
	}
	return res;
}
void clearr(int x){
	while(x){
		tr[x]=-1e9;
		x-=lowbit(x);
	}
}
int sum[200010][2];
int dp[200010];
bool cmp(int x,int y){
	return sum[x][1]==sum[y][1]?x<y:sum[x][1]<sum[y][1];
}
void cdq(int ll,int rr){
	if(ll==rr) return;
	int mid=(ll+rr)/2;
	cdq(ll,mid);
	dp[mid+1]=max(dp[mid+1],dp[mid]);
	vector<int>now;
	for(int s=ll;s<=min(ll+r+b-1,rr);s++){
		now.clear();
		for(int i=s;i<=rr;i+=r+b) now.push_back(i);
		sort(now.begin(),now.end(),cmp);
		for(int i:now) clearr(sum[i][0]);
		for(int i:now){
			if(i<=mid) update(sum[i][0],dp[i]-(i-s)/(r+b));
			else dp[i]=max(dp[i],query(sum[i][0])+(i-s)/(r+b));
		}
	}
	cdq(mid+1,rr);
}
char s[200005];
int a[200005];
signed main(){
	n=read(),r=read(),b=read();
	cin>>s+1;
	for(int i=1;i<=n;i++){
		sum[i][0]=sum[i-1][0]+(s[i]=='R'?-b:r);
		sum[i][1]=sum[i-1][1]+(s[i]=='B'?-r:b);
	}
	for(int i=1;i<=n+1;i++) a[i]=sum[i][0];
	sort(a+1,a+n+2);
	int m=unique(a+1,a+n+2)-a-1;
	for(int i=0;i<=n;i++) sum[i][0]=lower_bound(a+1,a+m+2,sum[i][0])-a;
	for(int i=1;i<=n+1;i++) a[i]=sum[i][1];
	sort(a+1,a+n+2);
	m=unique(a+1,a+n+2)-a-1;
	for(int i=0;i<=n;i++) sum[i][1]=lower_bound(a+1,a+m+2,sum[i][1])-a;
	cdq(0,n);
	write(dp[n]);
	return 0;
}