#include <fstream>
#include <vector>
#include <stdlib.h>
#include <time.h>
using namespace std;
ifstream cin("RT.in");
ofstream cout("RT.out");
 
int n,a,t, b_emp,b_o,ans = 0;
 
int cyf()
{	
	int i,j,k;
	cin >> n >> a >> b_emp;
	for(i = 1;i <= n;i++)
	{
		cin >> t;
		if(t == 1)
		{
			if(a >= 1)
			{
				a--;
				continue;
			}
			else if(a == 0&&b_emp >= 1)
			{
				b_emp--;
				b_o++;
				continue;
			}
			else if(a == 0&&b_o >= 1)
			{
				b_o--;
				continue;
			}
		}
		if(t == 2 && b_emp >= 1)
		{
			b_emp--;
			continue;
		}
		ans += t;
	}
	cout << ans << endl;
	cin.close();	
	cout.close();
	return 0;
}
int hhhh = cyf();
int main() {;}