#include <cstdio>
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <functional>
#include <queue>
#include <stack>
#include <cmath>
#include <iomanip>
 
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define CLR(a) memset((a), 0 ,sizeof(a))
#define MCLR(a) memset((a), -1 ,sizeof(a))

using namespace std;
const int MAX = 20000;
int INF = 99999999;

int main()
{
	int g,c,p;
	string s;

	cin >> g >> c >> p >> s;

	int point = 0;
	bool f[310];
	CLR(f);

	for(int i = 0;i < s.length();i++)
	{
		if(s[i] == 'G')
		{
			if(p)
			{
				p--;
				f[i] = true;
				point += 3;
			}
		}else
		if(s[i] == 'C')
		{
			if(g)
			{
				g--;
				f[i] = true;
				point += 3;
			}
		}else
		if(s[i] == 'P')
		{
			if(c)
			{
				c--;
				f[i] = true;
				point += 3;
			}
		}
	}

	for(int i = 0;i < s.length();i++)
	{
		if(s[i] == 'G' && !f[i])
		{
			if(g)
			{
				g--;
				point += 1;
			}
		}else
		if(s[i] == 'C' && !f[i])
		{
			if(c)
			{
				c--;
				point += 1;
			}
		}else
		if(s[i] == 'P' && !f[i])
		{
			if(p)
			{
				p--;
				point += 1;
			}
		}
	}

	cout << point << endl;

	return 0;
}