#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
inline int read(){
	int x=0,f=1;char c=getchar();
	while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
	while(c>='0'&&c<='9'){x=(x<<1)+(x<<3)+c-'0';c=getchar();}
	return x*f;
}
const int maxn=200010;
int n;
int dan,shuang;
int ans=0;
int main(){
	freopen("RT.in","r",stdin);
	freopen("RT.out","w",stdout);
	n=read();dan=read();shuang=read();
	shuang*=2;
	for(int i=1;i<=n;i++){
		int c=read();
		if(c==1){
			if(dan){
				dan--;
				continue;
			}
			if(shuang){
				shuang--;
				continue;
			}
			ans++;
			continue;
		}
		if(c==2){
			if(shuang&&shuang>=2){
				shuang-=2;
				continue;
			}
			ans+=2;
			continue;
		}
	}
	printf("%d\n",ans);
	return 0;
}