题目描述
Problem Statement
You are given a sequence of $non-negative integers A=(a_1,a_2,\ldots,a_N)$.
Let S be the set of non-negative integers that can be the sum of K terms in A (with distinct indices).
Find the greatest multiple of D in S. If there is no multiple of D in S, print -1 instead.
Input
The input is given from Standard Input in the following format:
N K D
$a_1 \ldots a_N$
Output
Print the answer.
Constraints
- $1 \leq K \leq N \leq 100$
- $1 \leq D \leq 100$
- $0 \leq a_i \leq 10^9$
- All values in the input are integers.
Sample Input 1
4 2 2
1 2 3 4
Sample Output 1
6
Here are all the ways to choose two terms in A.
- Choose a_1 and a_2, whose sum is 1+2=3.
- Choose a_1 and a_3, whose sum is 1+3=4.
- Choose a_1 and a_4, whose sum is 1+4=5.
- Choose a_2 and a_3, whose sum is 2+3=5.
- Choose a_2 and a_4, whose sum is 2+4=6.
- Choose a_3 and a_4, whose sum is 3+4=7.
Thus, we have S={3,4,5,6,7}. The greatest multiple of 2 in S is 6, so you should print 6.
Sample Input 2
3 1 2
1 3 5
Sample Output 2
-1
In this example, we have S={1,3,5}. Nothing in S is a multiple of 2, so you should print -1.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分