l, r, n = map(int, input().split()) for k in range(n): m_min = (l - k + n - 1) // n m_max_candidate = (r - k) // n x = m_max_candidate * n + k if x > r: m_max = m_max_candidate - 1 else: m_max = m_max_candidate if m_max < m_min: print(0) else: print(m_max - m_min + 1)