yuki = gets.chomp.split(' ').map {|i| i.to_i}
s = gets.chomp
aite = [s.scan('C').length, s.scan('P').length, s.scan('G').length]
#p yuki
#p s
#p aite
point = 0
(0...3).each do |i|
	if yuki[i] >= aite[i]
		point += 3 * aite[i]
		yuki[i] -= aite[i]
		aite[i] = 0
	else
		point += 3 * yuki[i]
		yuki[i] = 0
		aite[i] -= yuki[i]
	end
end
#puts point
#p aite.unshift(aite.pop)
#p aite
(0...3).each do |i|
	point += yuki[i]
end
puts point