#include <bits/stdc++.h>

using namespace std;

const int N = 1e4;

long long n, m;
long long a[N], v[N];
long long f[30][N + 10];

int main()
{
    cin >> n >> m;

    for(int i = 1; i <= n; i ++ ) cin >> a[i];
    for(int i = 1; i <= m; i ++ ) cin >> v[i];
    f[0][N / 2] = 1;

    for(int i = 1; i <= m; i ++ )
        for(int j = 1; j <= n; j ++ )
        {
            int p = v[i] * a[j];
            for (int k = N; k >= p; k -- )
                if (k - p <= N)
                    f[i][k] += f[i - 1][k - p];
        }
    cout << f[m][N / 2];

    return 0;
}