use strict;
use warnings;

my ($g, $c, $p) = split / /, <>;
my $s = <>;
chomp $s;
my @sa = split //, $s;
my $total = 0;
for(my $i = 0; $i < $#sa + 1; $i++) {
	if($sa[$i] eq 'G') {
		if($p > 0) {
			$total += 3;
			$p--;
		} elsif($g > 0) {
			$total++;
			$g--;
		} else {
			$c--;
		}
	} elsif($sa[$i] eq 'C') {
		if($g > 0) {
			$total += 3;
			$g--;
		} elsif($c > 0) {
			$total++;
			$c--;
		} else {
			$p--;
		}
	} else {
		if($c > 0) {
			$total += 3;
			$c--;
		} elsif($p > 0) {
			$total++;
			$p--;
		} else {
			$g--;
		}
	}
}

print "$total\n";

exit;