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

sc = int(raw_input())
t = raw_input()
vc = 0
vs = False
sl = 0

for s in t:
    if(s == 'U'):
        sl += 1
        if(vs and sl == 0):
            vs = False
            vc += 1
    else:
        if(sl == 0):
            vs = True
        sl -= 1
print vc