# Enter your code here. Read input from STDIN. Print output to STDOUT
i=raw_input()
steps=raw_input()
level = 0
valley=0
invalley=False
for s in steps:
    if s == "U":
        level = level+1
    else:
        level = level-1
    if level<0 and invalley==False:
        valley = valley+1
        invalley = True
    elif level == 0 and invalley:
        invalley=False
print valley