package main

import (
	"bufio"
	"fmt"
	"os"
)

const MOD int64 = 1000000007

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var m, n int
	if _, err := fmt.Fscan(in, &m, &n); err != nil {
		return
	}

	s := make([]int64, m)
	l := make([]int64, m)
	for i := 0; i < m; i++ {
		var x int64
		fmt.Fscan(in, &x)
		s[i] = x
	}
	for i := 0; i < m; i++ {
		var x int64
		fmt.Fscan(in, &x)
		l[i] = x
	}

	v := make([]int64, m)
	v[0] = 1

	for day := 0; day < n; day++ {
		var X, Y int64
		for i := 0; i < m; i++ {
			X = (X + v[i]*s[i]) % MOD
			Y = (Y + v[i]*l[i]) % MOD
		}
		newV := make([]int64, m)
		for j := 0; j < m; j++ {
			a := (s[j] + l[j]) % MOD
			newV[j] = (a*X + (s[j]%MOD)*Y) % MOD
		}
		v = newV
	}

	var ans int64
	for i := 0; i < m; i++ {
		ans = (ans + v[i]) % MOD
	}
	fmt.Fprintln(out, ans)
}