import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int G = sc.nextInt();
		int C = sc.nextInt();
		int P = sc.nextInt();
		String S = sc.next();
		
		int ans = 0;
		String nextS = "";
		
		//勝てる手
		for(int i=0; i<S.length(); i++) {
			
			char look = S.charAt(i);
			boolean find = false;
			
			if(look == 'G') {
				if(P>0) { P--; ans+=3; find=true; }
				
			} else if(look == 'C') {
				if(G>0) { G--; ans+=3; find=true; }
				
			} else if(look == 'P') {
				if(C>0) { C--; ans+=3; find=true; }
			}
		
			if(find==false) {
				nextS += look;
			}
		}
		
		S = nextS;
		
		//あいこの手
		for(int i=0; i<S.length(); i++) {
			
			char look = S.charAt(i);
			
			if(look == 'G') {
				if(G>0) { G--; ans+=1; }
				
			} else if(look == 'C') {
				if(C>0) { C--; ans+=1; }
				
			} else if(look == 'P') {
				if(P>0) { P--; ans+=1; }
			}	
		}
		System.out.println(ans);
	}
}