# Enter your code here. Read input from STDIN. Print output to STDOUT
n = int(raw_input())
s = raw_input()
elev = 0
valleys = 0
for i in s:
    if i == 'D':
        if elev == 0:
            valleys += 1
        elev -= 1
    elif i == 'U':
        elev += 1
print valleys