# Enter your code here. Read input from STDIN. Print output to STDOUT
#!/bin/python

n = int(raw_input().strip())
height = list(raw_input())

count = 0
valley = 0


for i in height:
    if i == "U":
        count += 1
    else:
        if count == 0:
            count -= 1
            valley += 1
        else:
            count -=1

print valley