def valleys(steps):
    count = 0
    valleys = 0
    is_valley = False

    for step in steps:
        if step == 'U':
            count += 1
            if count == 0 and is_valley:
                is_valley = False
        else:
            count -= 1
            if count < 0 and not is_valley:
                valleys += 1
                is_valley = True

    return valleys


if __name__ == '__main__':
    walk = input()
    steps = list(raw_input())
    print valleys(steps)