import sys


n = int(input().strip())
seq = input().strip()
height = 0
valley = False
num_valley = 0

for i in seq:
    if height == 0:
        if i == 'U':
            valley = False
            height += 1
        else:
            valley = True
            height -= 1
    elif valley and height < 0:
        if i == 'U':
            height += 1
            if height == 0:
                num_valley += 1
        else:
            height -= 1
    elif not valley and height > 0:
        if i == 'U':
            height += 1
        else:
            height -= 1

print(num_valley)