#include <bits/stdc++.h>
#define endl '\n'
using namespace std;
using ll = long long;

ll dp[3010][3010];
int n,m;
ll pre[3010];
ll a[3010];
ll b[3010];
ll MOD = 1000000007;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    freopen("DIVGROUP.INP","r",stdin);
    freopen("DIVGROUP.OUT","w",stdout);
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        pre[i] += pre[i-1] + a[i];
    }
    for(int j = 1; j <= m; j++){
        cin >> b[j];
    }
    dp[0][0] = 1;
    for(int j = 1; j <= m; j++){
        for(int i = j; i <= n; i++){
            for(int k = j - 1; k < i; k++){
                if((pre[i] - pre[k]) % b[j] == 0){
                    dp[i][j] = (dp[i][j] + dp[k][j-1]) % MOD;
                }
            }
        }
    }
    cout << dp[n][m];
    return 0;
}