def valleycount(climb):
    sealevel = 0
    counter = 0
    for letter in climb:
        if sealevel == 0 and letter == 'D':
            counter+=1
            sealevel-=1
        elif letter == 'U':
            sealevel+=1
        else:
            sealevel-=1
    print counter


n = raw_input()
path = list(raw_input())
valleycount(path)