input()
steps = input()

valleys = 0
elevation = 0
was_below_sea_level = False

for step in steps:
    elevation += (1 if step == 'U' else -1)
    
    if elevation < 0:
        was_below_sea_level = True
    
    elif elevation is 0 and was_below_sea_level:
        valleys += 1
        was_below_sea_level = False

print(valleys)