# Enter your code here. Read input from STDIN. Print output to STDOUT
n=int(raw_input())
steps=raw_input()
sea_level=0
enter_valley=False
valley_count=0
for step in steps:
  
    if step=="U":
        sea_level+=1
    else:
        sea_level-=1
    if sea_level>0:
        continue
    if sea_level<0 and enter_valley==False:
        enter_valley=True
        valley_count=valley_count+1
    if sea_level==0 and enter_valley==True:
        enter_valley=False
print valley_count