using CompLib.Collections.Generic;
using CompLib.Util;
using System;
using System.Collections.Generic;
using System.Text;

public class Program
{
    int N, M;
    int[] S, T;
    public void Solve()
    {
        var sc = new Scanner();
        N = sc.NextInt();
        M = sc.NextInt();
        S = sc.IntArray();
        T = sc.IntArray();

        var ar = new ModInt[N + 1];
        for (int i = 0; i <= N; i++)
        {
            ar[i] = 1;
        }

        for (int i = 0; i < M; i++)
        {
            ModInt t = 0;
            ModInt[] p = new ModInt[N + 1];
            for (int j = 0; j < N; j++)
            {
                p[j] = t;
                if (S[j] == T[i])
                {
                    t += ar[j];
                }
            }
            p[N] = t;

            for (int j = 0; j <=N; j++)
            {
                ar[j] += p[j];
            }

           // Console.WriteLine(string.Join(" ", ar));
        }

        Console.WriteLine(ar[N]);
    }

    public static void Main(string[] args) => new Program().Solve();
}

namespace CompLib.Collections.Generic
{
    using System;

    public class RangeUpdateQuery<T>
    {
        // 制約に合った2の冪
        private const int N = 1 << 21;
        private T[] _array;
        private readonly bool[] flag;

        private readonly T _identity;
        private readonly Func<T, T, T> _operation;

        /// <summary>
        /// 区間更新、点取得
        /// </summary>
        /// <param name="operation">更新用の演算</param>
        /// <param name="identity">(T, operation)の左単位元</param>
        public RangeUpdateQuery(Func<T, T, T> operation, T identity)
        {
            _identity = identity;
            _operation = operation;
            _array = new T[N * 2];
            for (int i = 1; i < N * 2; i++)
            {
                _array[i] = _identity;
            }

            flag = new bool[N * 2];
        }

        private void Eval(int k, int l, int r)
        {
            if (flag[k])
            {
                if (r - l > 1)
                {
                    _array[k * 2] = _operation(_array[k * 2], _array[k]);
                    flag[k * 2] = true;
                    _array[k * 2 + 1] = _operation(_array[k * 2 + 1], _array[k]);
                    flag[k * 2 + 1] = true;
                    _array[k] = _identity;
                }

                flag[k] = false;
            }
        }

        private void Update(int left, int right, int k, int l, int r, T item)
        {
            Eval(k, l, r);
            if (r <= left || right <= l)
            {
                return;
            }

            if (left <= l && r <= right)
            {
                _array[k] = _operation(_array[k], item);
                flag[k] = true;
                Eval(k, l, r);
                return;
            }

            Update(left, right, k * 2, l, (l + r) / 2, item);
            Update(left, right, k * 2 + 1, (l + r) / 2, r, item);
        }

        /// <summary> 
        /// [left,right)をoperation(A[i],item)に更新
        /// </summary>
        /// <param name="left"></param>
        /// <param name="right"></param>
        /// <param name="item"></param>
        public void Update(int left, int right, T item)
        {
            Update(left, right, 1, 0, N, item);
        }


        /// <summary>
        /// A[i]を取得 O(log N)
        /// </summary>
        /// <param name="i"></param>
        /// <returns></returns>
        public T Get(int i)
        {
            int l = 0;
            int r = N;
            int k = 1;
            while (r - l > 1)
            {
                Eval(k, l, r);
                int m = (l + r) / 2;
                if (i < m)
                {
                    r = m;
                    k = k * 2;
                }
                else
                {
                    l = m;
                    k = k * 2 + 1;
                }
            }

            return _array[k];
        }

        public T this[int i]
        {
            get { return Get(i); }
        }
    }
}
#region ModInt
/// <summary>
/// [0,<see cref="Mod"/>) までの値を取るような数
/// </summary>
public struct ModInt
{
    /// <summary>
    /// 剰余を取る値．
    /// </summary>
    public const long Mod = (int)1e9 + 7;

    /// <summary>
    /// 実際の数値．
    /// </summary>
    public long num;
    /// <summary>
    /// 値が <paramref name="n"/> であるようなインスタンスを構築します．
    /// </summary>
    /// <param name="n">インスタンスが持つ値</param>
    /// <remarks>パフォーマンスの問題上，コンストラクタ内では剰余を取りません．そのため，<paramref name="n"/> ∈ [0,<see cref="Mod"/>) を満たすような <paramref name="n"/> を渡してください．このコンストラクタは O(1) で実行されます．</remarks>
    public ModInt(long n) { num = n; }
    /// <summary>
    /// このインスタンスの数値を文字列に変換します．
    /// </summary>
    /// <returns>[0,<see cref="Mod"/>) の範囲内の整数を 10 進表記したもの．</returns>
    public override string ToString() { return num.ToString(); }
    public static ModInt operator +(ModInt l, ModInt r) { l.num += r.num; if (l.num >= Mod) l.num -= Mod; return l; }
    public static ModInt operator -(ModInt l, ModInt r) { l.num -= r.num; if (l.num < 0) l.num += Mod; return l; }
    public static ModInt operator *(ModInt l, ModInt r) { return new ModInt(l.num * r.num % Mod); }
    public static implicit operator ModInt(long n) { n %= Mod; if (n < 0) n += Mod; return new ModInt(n); }

    /// <summary>
    /// 与えられた 2 つの数値からべき剰余を計算します．
    /// </summary>
    /// <param name="v">べき乗の底</param>
    /// <param name="k">べき指数</param>
    /// <returns>繰り返し二乗法により O(N log N) で実行されます．</returns>
    public static ModInt Pow(ModInt v, long k) { return Pow(v.num, k); }

    /// <summary>
    /// 与えられた 2 つの数値からべき剰余を計算します．
    /// </summary>
    /// <param name="v">べき乗の底</param>
    /// <param name="k">べき指数</param>
    /// <returns>繰り返し二乗法により O(N log N) で実行されます．</returns>
    public static ModInt Pow(long v, long k)
    {
        long ret = 1;
        for (k %= Mod - 1; k > 0; k >>= 1, v = v * v % Mod)
            if ((k & 1) == 1) ret = ret * v % Mod;
        return new ModInt(ret);
    }
    /// <summary>
    /// 与えられた数の逆元を計算します．
    /// </summary>
    /// <param name="v">逆元を取る対象となる数</param>
    /// <returns>逆元となるような値</returns>
    /// <remarks>法が素数であることを仮定して，フェルマーの小定理に従って逆元を O(log N) で計算します．</remarks>
    public static ModInt Inverse(ModInt v) { return Pow(v, Mod - 2); }
}
#endregion

namespace CompLib.Util
{
    using System;
    using System.Linq;
    class Scanner
    {
        private int _index;
        private string[] _line;
        const char separator = ' ';

        public Scanner()
        {
            _index = 0;
            _line = new string[0];
        }

        public string Next()
        {
            while (_index >= _line.Length)
            {
                _line = Console.ReadLine().Split(separator);
                _index = 0;
            }
            return _line[_index++];
        }
        public int NextInt() => int.Parse(Next());
        public long NextLong() => long.Parse(Next());
        public double NextDouble() => double.Parse(Next());
        public char NextChar() => Next()[0];
        public char[] NextCharArray() => Next().ToCharArray();

        public string[] Array()
        {
            _line = Console.ReadLine().Split(separator);
            _index = _line.Length;
            return _line;
        }
        public int[] IntArray() => Array().Select(int.Parse).ToArray();
        public long[] LongArray() => Array().Select(long.Parse).ToArray();
        public double[] DoubleArray() => Array().Select(double.Parse).ToArray();
    }
}

Measured memory_bytes: 30688