NCIS

#define task "NCIS"
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 1e4 + 5;
constexpr int mod = 123456789;
int m, n, last[N * 2];
int a[N], b[N], dp[N], f[N];
vector<int> s;

void Read()
{
    cin >> m >> n;

    for (int i = 1; i <= m; ++i)
    {
        cin >> a[i];
        s.emplace_back(a[i]);
    }

    for (int i = 1; i <= n; ++i)
    {
        cin >> b[i];
        s.emplace_back(b[i]);
    }
}

#define Find(x, v) (lower_bound(x.begin(), x.end(), v) - x.begin() + 1)
void Compress()
{
    sort(s.begin(), s.end());
    s.resize(unique(s.begin(), s.end()) - s.begin());

    for (int i = 1; i <= m; ++i)
        a[i] = Find(s, a[i]);
    for (int i = 1; i <= n; ++i)
        b[i] = Find(s, b[i]);
}

void Solve()
{
    dp[0] = 1;

    for (int i = 1; i <= m; ++i)
    {
        int res(0);

        for (int j = 1; j <= n; ++j)
            last[b[j]] = 0;

        for (int j = 0; j <= n; ++j)
        {
            if (a[i] == b[j])
                f[j] = res;
            else
            {
                f[j] = dp[j];

                if (b[j] < a[i])
                {
                    (res += dp[j]) %= mod;
                    if (last[b[j]] > 0)
                        (res -= dp[last[b[j]]]) %= mod;
                }
            }

            last[b[j]] = j;
        }

        swap(f, dp);
    }

    int ans(0);

    for (int i = 1; i <= n; ++i)
        if (i == last[b[i]])
            (ans += dp[i]) %= mod;

    cout << (ans + mod) % mod;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }

    Read();
    Compress();
    Solve();
}