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A9978. Duff in Beach

编程题 普及/提高-

题目描述

While Duff was resting in the beach, she accidentally found a strange array $b_{0},b_{1},...,b_{l-1}$ consisting of $l$ positive integers. This array was strange because it was extremely long, but there was another (maybe shorter) array, $a_{0},...,a_{n-1}$ that $b$ can be build from $a$ with formula: $b_{i}=a_{i\ mod\ n}$ where $a\ mod\ b$ denoted the remainder of dividing $a$ by $b$ .

![](/uploads/acgo/image/9d5711ed4bf6629a_007c38861cb6.jpeg)Duff is so curious, she wants to know the number of subsequences of $b$ like $b_{i1},b_{i2},...,b_{ix}$ ( $0<=i_{1}<i_{2}<...<i_{x}<l$ ), such that:

- $1<=x<=k$
- For each $1<=j<=x-1$ , ![](/uploads/acgo/image/b30b9a6cbeb3e73a_3b49abd89637.jpeg)
- For each $1<=j<=x-1$ , $b_{ij}<=b_{ij+1}$ . i.e this subsequence is non-decreasing.

Since this number can be very large, she want to know it modulo $10^{9}+7$ .

Duff is not a programmer, and Malek is unavailable at the moment. So she asked for your help. Please tell her this number.

输入格式

The first line of input contains three integers, $n,l$ and $k$ ( $1<=n,k$ , $n×k<=10^{6}$ and $1<=l<=10^{18}$ ).

The second line contains $n$ space separated integers, $a_{0},a_{1},...,a_{n-1}$ ( $1<=a_{i}<=10^{9}$ for each $0<=i<=n-1$ ).

输出格式

Print the answer modulo $1000000007$ in one line.

输入输出样例

输入 #1
3 5 3
5 9 1
输出 #1
10
输入 #2
5 10 3
1 2 3 4 5
输出 #2
25

说明/提示

In the first sample case, ![](/uploads/luogu/CF587B/e203c59fa4514192459985b0817cae7e512099c6_a3357be03e3d.png). So all such sequences are: ![](/uploads/luogu/CF587B/00e4e91cd4a594888eedcd67c9e69d4094a90345_c02b9b31eb0e.png), ![](/uploads/luogu/CF587B/cdd3e3d0d956421d5d8cd2838632f4e3cd7d0af4_01ae51ee88ff.png), ![](/uploads/luogu/CF587B/7f7b139a743d7ce88b395499128708f29bfdf0b9_966f70251f4e.png), ![](/uploads/luogu/CF587B/12393dcd04e9e0850ef671f96dabfb383ce97878_f04b9092b03b.png), ![](/uploads/luogu/CF587B/4b220af8de32b09043405b2bd6363ded2eefca0f_4ea017192082.png), ![](/uploads/luogu/CF587B/e21e90924631a3c49468ec23e21216d6442c4e0f_1be59d6b63b4.png), ![](/uploads/luogu/CF587B/6ae4c31a3e68cdea3eb504c050a788cbffe73451_fc7ae85349c7.png), ![](/uploads/luogu/CF587B/acccff29063f66eddd3e6f721a68b757f796bd6c_7771a4a3487c.png), ![](/uploads/luogu/CF587B/e585e51cc52e2383c99bfb65a5a7624c6504daec_5763b035e96f.png) and ![](/uploads/acgo/image/82404f4480730dfc_5afe973fdad2.jpeg).
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