Problem: You are given an integer sequence of length N: A_1,A_2,...,A_N. Let us perform Q operations in order. The i-th operation is described by two integers X_i and Y_i. In this operation, we will choose one of the following two actions and perform it:

* Swap the values of A_{X_i} and A_{Y_i}
* Do nothing



There are 2^Q ways to perform these operations. Find the sum of the inversion numbers of the final sequences for all of these ways to perform operations, modulo 10^9+7.

Here, the inversion number of a sequence P_1,P_2,...,P_M is the number of pairs of integers (i,j) such that 1\leq i < j\leq M and P_i > P_j.

Constraints

* 1 \leq N \leq 3000
* 0 \leq Q \leq 3000
* 0 \leq A_i \leq 10^9(1\leq i\leq N)
* 1 \leq X_i,Y_i \leq N(1\leq i\leq Q)
* X_i\neq Y_i(1\leq i\leq Q)
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N Q
A_1
:
A_N
X_1 Y_1
:
X_Q Y_Q


Output

Print the sum of the inversion numbers of the final sequences, modulo 10^9+7.

Examples

Input

3 2
1
2
3
1 2
1 3


Output

6


Input

5 3
3
2
3
1
4
1 5
2 3
4 2


Output

36


Input

9 5
3
1
4
1
5
9
2
6
5
3 5
8 9
7 9
3 2
3 8


Output

425

Solution (in CPP):

Solution:
#include<iostream>
#define int long long
using namespace std;
const int P=1e9+7,inv2=5e8+4;
int f[3100][3100],A[3100],bs,Q,n,ans;
signed main()
{
	cin>>n>>Q;
	for(int i=1;i<=n;i++) cin>>A[i];
	for(int i=1;i<=n;i++)
		for(int j=1;j<=n;j++)
			if(A[i]<A[j]) f[i][j]=1;
	for(int w=1;w<=Q;w++)
	{
		int x,y;cin>>x>>y;
		for(int i=1;i<=n;i++)
		{
			if(x==i||y==i) continue;
			int t1=inv2*(f[i][x]+f[i][y])%P;
			int t2=inv2*(f[x][i]+f[y][i])%P;
			f[i][x]=f[i][y]=t1;
			f[x][i]=f[y][i]=t2;
		}
		f[x][y]=f[y][x]=inv2*(f[x][y]+f[y][x])%P;
	}
	for(int i=bs=1;i<=Q;i++) bs=2*bs%P;
	for(int i=1;i<=n;i++)
		for(int j=1;j<i;j++)
			(ans+=bs*f[i][j])%=P;
	cout<<ans<<endl;
}