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

inp = raw_input()
xs = raw_input()

level = 0
in_valley = True
valley_count = 0
level_seq = []
for x in xs :
    if x == "U" :
        level += 1
        if level == 0 and in_valley :
            valley_count += 1
            in_valley = False
    elif x == "D" :
        level -= 1
        if level == -1 and not in_valley :
            in_valley = True
    elif x == "_" :
        level = 0
    level_seq += [level]
print valley_count