a = input()
b = raw_input()

count = 0
level = 0
flag = 0
for i in b:
    if i == "U":
        level += 1
    else:
        level -= 1

    if level < 0:
        flag = 1

    if flag == 1 and level == 0:
        count += 1
        flag = 0


print count