num_valleys = 0

num_steps = int(raw_input().strip())
all_steps = raw_input()

altitude = 0

for this_step_number in xrange(num_steps):
    this_step = all_steps[this_step_number]
    new_altitude = altitude + (1 if this_step == "U" else -1)
    if altitude == 0 and new_altitude < 0:
        num_valleys += 1
    altitude = new_altitude

print num_valleys