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

def valleys():
    n = int(input())
    s = sys.stdin.readline()
    somme = 0
    nValleys = 0
    for i in range(n):
        if s[i] == 'D':
            somme -= 1
        if s[i] == 'U':
            somme += 1
            if somme == 0:
                nValleys += 1
    print nValleys
    
valleys()