2493: Duff in Beach
Description
While Duff was resting in the beach, she accidentally found a strange array b0,b1,...,bl-1 consisting of l positive integers. This array was strange because it was extremely long, but there was another (maybe shorter) array, a0,...,an-1 that b can be build from a with formula: bi=ai mod n where a mod b denoted the remainder of dividing a by b.
Duff is so curious, she wants to know the number of subsequences of b like bi1,bi2,...,bix (0≤i1<i2<...<ix<l), such that:
- 1≤x≤k
- For each 1≤j≤x-1,
- For each 1≤j≤x-1, bij≤bij+1. i.e this subsequence is non-decreasing.
Since this number can be very large, she want to know it modulo 109+7.
Duff is not a programmer, and Malek is unavailable at the moment. So she asked for your help. Please tell her this number.
The first line of input contains three integers, n,l and k (1≤n,k, n×k≤106 and 1≤l≤1018).
The second line contains n space separated integers, a0,a1,...,an-1 (1≤ai≤109 for each 0≤i≤n-1).
Print the answer modulo 1000000007 in one line.
3 5 3
5 9 1
10
5 10 3
1 2 3 4 5
25
In the first sample case, . So all such sequences are: , , , , , , , , and .