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Description
可乐加冰有n栈电灯泡,编号为1-n,每个灯泡都有一个开关。那么问题来了 1.所有灯泡初始时为不亮的 2.可乐加冰分别进行三次操作 3.每次操作他都选一个质数x,将编号为x和x的整数倍的灯泡的开关都拨动一下(如果灯为亮,那么拨动以后灯为不亮,如果灯不亮,拨动以后变为亮)
求最后亮着的灯的数量
Format
Input
每组第一行一个n表示灯泡个数(1<=n<=10^9)
第二行三个数a,b,c表示可乐加冰每次选择的数(1<=a,b,c<=10^6)(a,b,c全为质数且a,b,c两两互不相等)
Output
求最后亮着的灯的数量
Samples
30
2 3 5
15
Limitation
1s, 1024KiB for each test case.
2022-2023学年周赛(10)暨蓝桥杯训练赛
- Status
- Done
- Rule
- ACM/ICPC
- Problem
- 6
- Start at
- 2023-3-5 8:30
- End at
- 2023-3-5 12:00
- Duration
- 3.5 hour(s)
- Host
- Partic.
- 32