# Enter your code here. Read input from STDIN. Print output to STDOUT inp = raw_input() xs = raw_input() level = 0 in_valley = True valley_count = 0 level_seq = [] for x in xs : if x == "U" : level += 1 if level == 0 and in_valley : valley_count += 1 in_valley = False elif x == "D" : level -= 1 if level == -1 and not in_valley : in_valley = True elif x == "_" : level = 0 level_seq += [level] print valley_count