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A10544. Pineapple Incident

编程题 普及/提高-

题目描述

Ted has a pineapple. This pineapple is able to bark like a bulldog! At time $t$ (in seconds) it barks for the first time. Then every $s$ seconds after it, it barks twice with $1$ second interval. Thus it barks at times $t$ , $t+s$ , $t+s+1$ , $t+2s$ , $t+2s+1$ , etc.

![](/uploads/acgo/image/42abdb164563c199_c988baa4b15a.jpeg)Barney woke up in the morning and wants to eat the pineapple, but he can't eat it when it's barking. Barney plans to eat it at time $x$ (in seconds), so he asked you to tell him if it's gonna bark at that time.

输入格式

The first and only line of input contains three integers $t$ , $s$ and $x$ ( $0<=t,x<=10^{9}$ , $2<=s<=10^{9}$ ) — the time the pineapple barks for the first time, the pineapple barking interval, and the time Barney wants to eat the pineapple respectively.

输出格式

Print a single "YES" (without quotes) if the pineapple will bark at time $x$ or a single "NO" (without quotes) otherwise in the only line of output.

输入输出样例

输入 #1
3 10 4
输出 #1
NO
输入 #2
3 10 3
输出 #2
YES
输入 #3
3 8 51
输出 #3
YES
输入 #4
3 8 52
输出 #4
YES

说明/提示

In the first and the second sample cases pineapple will bark at moments $3$ , $13$ , $14$ , ..., so it won't bark at the moment $4$ and will bark at the moment $3$ .

In the third and fourth sample cases pineapple will bark at moments $3$ , $11$ , $12$ , $19$ , $20$ , $27$ , $28$ , $35$ , $36$ , $43$ , $44$ , $51$ , $52$ , $59$ , ..., so it will bark at both moments $51$ and $52$ .
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