# Time Limit: 5 Sec Memory Limit: 64 MB Submit: 667 Solved: 389 [Submit][Status][Discuss]
Description # 贝茜是一只非常努力工作的奶牛，她总是专注于提高自己的产量。为了产更多的奶，她预计好了接下来的N (1 ≤ N ≤ 1,000,000)个小时，标记为0..N-1。 Farmer John 计划好了 M (1 ≤ M ≤ 1,000) 个可以挤奶的时间段。每个时间段有一个开始时间(0 ≤ 开始时间 ≤ N), 和一个结束时间 (开始时间 < 结束时间 ≤ N), 和一个产量 (1 ≤ 产量 ≤ 1,000,000) 表示可以从贝茜挤奶的数量。Farmer John 从分别从开始时间挤奶，到结束时间为止。每次挤奶必须使用整个时间段。 但即使是贝茜也有她的产量限制。每次挤奶以后，她必须休息 R (1 ≤ R ≤ N) 个小时才能下次挤奶。给定Farmer John 计划的时间段，请你算出在 N 个小时内，最大的挤奶的量。
1641: [Usaco2007 Nov]Cow Hurdles 奶牛跨栏 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 531 Solved: 344 [Submit][Status][Discuss]
1640: [Usaco2007 Nov]Best Cow Line 队列变换 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 710 Solved: 373 [Submit][Status][Discuss]
1639: [Usaco2007 Mar]Monthly Expense 月度开支 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 767 Solved: 381 [Submit][Status][Discuss]
1637: [Usaco2007 Mar]Balanced Lineup # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 503 Solved: 336 [Submit][Status][Discuss]
1635: [Usaco2007 Jan]Tallest Cow 最高的牛 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 472 Solved: 278 [Submit][Status][Discuss]
1634: [Usaco2007 Jan]Protecting the Flowers 护花 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 605 Solved: 383 [Submit][Status][Discuss]
1632: [Usaco2007 Feb]Lilypad Pond # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 496 Solved: 153 [Submit][Status][Discuss]
2023: [Usaco2005 Nov]Ant Counting 数蚂蚁 # Time Limit: 4 Sec Memory Limit: 64 MB Submit: 149 Solved: 85 [Submit][Status][Discuss]
1629: [Usaco2007 Demo]Cow Acrobats # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 771 Solved: 398 [Submit][Status][Discuss]
1628: [Usaco2007 Demo]City skyline # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 396 Solved: 317 [Submit][Status][Discuss]
1627: [Usaco2007 Dec]穿越泥地 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 624 Solved: 411 [Submit][Status][Discuss]
1626: [Usaco2007 Dec]Building Roads 修建道路 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 1362 Solved: 541 [Submit][Status][Discuss]
1624: [Usaco2008 Open] Clear And Present Danger 寻宝之路 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 507 Solved: 345 [Submit][Status][Discuss]
1623: [Usaco2008 Open]Cow Cars 奶牛飞车 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 386 Solved: 266 [Submit][Status][Discuss]
1622: [Usaco2008 Open]Word Power 名字的能量 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 462 Solved: 228 [Submit][Status][Discuss]
1621: [Usaco2008 Open]Roads Around The Farm分岔路口 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 698 Solved: 513 [Submit][Status][Discuss]
1620: [Usaco2008 Nov]Time Management 时间管理 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 636 Solved: 387 [Submit][Status][Discuss]
1619: [Usaco2008 Nov]Guarding the Farm 保卫牧场 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 661 Solved: 292 [Submit][Status][Discuss]
1618: [Usaco2008 Nov]Buying Hay 购买干草 # Time Limit: 5 Sec Memory Limit: 64 MB Submit: 906 Solved: 456 [Submit][Status][Discuss]