# Enter your code here. Read input from STDIN. Print output to STDOUT

n_steps = STDIN.readline.to_i()

steps = STDIN.readline.chomp()

features = []
level = 0

steps.each_char { |chr|
	
	if level == 0
		features << 0
	else
		features[-1] += level
	end

	level += (chr == "U" ? 1 : -1)
}

p features.count {|e| e < 0 }