import java.io.*;
import java.util.*;
import java.math.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		String[] line = br.readLine().split(" ");
		int g = Integer.parseInt(line[0]);
		int c = Integer.parseInt(line[1]);
		int p = Integer.parseInt(line[2]);
		char[] h = br.readLine().toCharArray();
		
		int ans = 0;
		for (int i = 0; i < h.length; i++) {
			if (h[i] == 'G') {
				if (p > 0) {
					p--;
					ans += 3;
				} else if (g > 0) {
					g--;
					ans++;
				} else {
					c--;
				}
			} else if (h[i] == 'C') {
				if (g > 0) {
					g--;
					ans += 3;
				} else if (c > 0) {
					c--;
					ans++;
				} else {
					p--;
				}
			} else {
				if (c > 0) {
					c--;
					ans += 3;
				} else if (p > 0) {
					p--;
					ans++;
				} else {
					g--;
				}
			}
		}
		
		out(ans);
	}
}