A11472. Cave Painting
编程题
普及/提高-
知识点
题目描述
Imp is watching a documentary about cave painting.
Some numbers, carved in chaotic order, immediately attracted his attention. Imp rapidly proposed a guess that they are the remainders of division of a number $n$ by all integers $i$ from $1$ to $k$ . Unfortunately, there are too many integers to analyze for Imp.
Imp wants you to check whether all these remainders are distinct. Formally, he wants to check, if all , $1<=i<=k$ , are distinct, i. e. there is no such pair $(i,j)$ that:
- $1 \leq i < j \leq k$ ,
- , where  is the remainder of division $x$ by $y$ .
Some numbers, carved in chaotic order, immediately attracted his attention. Imp rapidly proposed a guess that they are the remainders of division of a number $n$ by all integers $i$ from $1$ to $k$ . Unfortunately, there are too many integers to analyze for Imp.
Imp wants you to check whether all these remainders are distinct. Formally, he wants to check, if all , $1<=i<=k$ , are distinct, i. e. there is no such pair $(i,j)$ that:
- $1 \leq i < j \leq k$ ,
- , where  is the remainder of division $x$ by $y$ .
输入格式
The only line contains two integers $n$ , $k$ $(1<=n,k<=10^{18})$ .
输出格式
Print "Yes", if all the remainders are distinct, and "No" otherwise.
You can print each letter in arbitrary case (lower or upper).
You can print each letter in arbitrary case (lower or upper).
输入输出样例
输入 #1
4 4
输出 #1
No
输入 #2
5 3
输出 #2
Yes
说明/提示
In the first sample remainders modulo $1$ and $4$ coincide.