# import sys; input = sys.stdin.buffer.readline # sys.setrecursionlimit(10**7) from collections import defaultdict con = 10 ** 9 + 7; INF = float("inf") def getlist(): return list(map(int, input().split())) #処理内容 def main(): L, R, N = getlist() l = int(L // N) r = int(R // N) ld = L % N rd = R % N pre = r - l for i in range(N): ans = pre if i < ld: ans -= 1 if i <= rd: ans += 1 print(ans) if __name__ == '__main__': main()