D. Longest Subsequence

D. Longest Subsequence

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

You are given array a with
n elements and the number m. Consider some subsequence of
a and the value of least common multiple (LCM) of its elements. Denote LCM as
l. Find any longest subsequence of
a with the value l ≤ m.

A subsequence of a is an array we can get by erasing some elements of
a. It is allowed to erase zero or all elements.

The LCM of an empty array equals 1.

Input

The first line contains two integers n and
m (1 ≤ n, m ≤ 10⁶) — the size of the array
a and the parameter from the problem statement.

The second line contains n integers
a_i (1 ≤ a_i ≤ 10⁹) — the elements of
a.

Output

In the first line print two integers l and
k_max (1 ≤ l ≤ m, 0 ≤ k_max ≤ n) — the value of LCM and the number of elements
in optimal subsequence.

In the second line print k_max integers — the positions of the elements from the optimal subsequence in the ascending order.

Note that you can find and print any subsequence with the maximum length.

Examples

Input

7 8
6 2 9 2 7 2 3

Output

6 5
1 2 4 6 7

Input

6 4
2 2 2 3 3 3

Output

2 3

1 2 3


/*题目大意：给定n大小的数组a，求数组a的最长子序列的最小公倍数不超过m。要求输出其满足要求的任意子序列
 *算法分析：先将小于等于m的数择出来，然后从后向前筛
*/
#include <bits/stdc++.h>
using namespace std;

typedef long long int llint;
const int maxn = 1e6 + 100;
llint a[maxn], b[maxn];

int main() {
	memset(a, 0, sizeof(a));
	memset(b, 0, sizeof(b));
	llint n, m, flag = 0;
	scanf("%I64d%I64d",&n, &m);
	for (llint i = 0; i<n; i++) {
		scanf("%I64d",&a[i]);
		if (a[i] <= m) {
			b[a[i]] ++ ;
			flag = 1;
		}
	}
	if (!flag)	cout << "1 0" << endl;
	else {
		for (llint i = m; i>=1; i--) {
			for (llint j = 2*i; j<=m; j+=i) {
				b[j] += b[i];
			}
		}
		llint max = 0, lcm = 0;
		for (llint i = 1; i<=m; i++) {
			if (b[i] > max) {
				max = b[i];
				lcm = i;
			}
		}
		cout << lcm << " " << max << endl;
		for (llint i = 0; i<n; i++) {
			if (lcm%a[i] == 0)	cout << i+1 << " " ;
		}
		cout << endl;
	}
	return 0;
}