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

n = input()
steps = raw_input()

sea_level = 0
valley_started = False
result=0
for i in steps:
    if i == 'D' and sea_level == 0:
        valley_started = True
    if i == 'D':
        sea_level-=1
    else:
        sea_level+=1
    if sea_level == 0 and valley_started==True:
        valley_started = False
        result+=1
print result