# Enter your code here. Read input from STDIN. Print output to STDOUT
n=int(raw_input())
s=raw_input().upper()
countv=0
count=0
for i in range(0,len(s)):
    if s[i]=='D':
        count-=1
    elif s[i]=='U':
        count+=1
    if count==0 and s[i]=='U':
        countv+=1
print countv