#include <bits/stdc++.h>
/**
 5 2
 200 145 240 50 45
 150 300
 答案
 4
 */
using namespace std;
int m, n;
const int N = 310;
int a[N], b[N];
int res;
void dfs(int u, int s) {
    if (u == n + 1) {
        res = max(res, s);
        return;
    }

    dfs(u + 1, s);

    for (int i = 1; i <= m; i++)
        if (a[u] <= b[i]) {
            b[i] -= a[u]; //回溯
            dfs(u + 1, s + 1);
            b[i] += a[u];
        }
}
int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= m; i++) cin >> b[i];
    dfs(1, 0);
    printf("%d\n", res);
    return 0;
}