# code template

from sys import stdin

def get():
	return testcase.next().strip()


testcase = stdin
# solution starts here

get()
s = get()

current = 0
count = 0
que = False

for i in s:
	if i == "U":
		current += 1
		if current == 0:
			if que:
				count += 1
				que = False
	elif i == "D":
		current -= 1
		if current == -1 and not que:
			que = True
print count