#include <iostream>

using namespace std;

const int N = 22;
int n, m;
int res = N;
int a[N];

void dfs(int u, int cnt, int sum)
{
    if (sum == m) res = min(res, cnt);
    if (u < 0 || sum > m) return;

    dfs(u - 1, cnt + 1, sum + a[u]);
    dfs(u - 1, cnt, sum);
}

int main()
{
    cin >> m >> n;
    for (int i = 0; i < n; i ++ )
        cin >> a[i];

    dfs(n - 1, 0, 0);

    if (res == N) cout << 0 << endl;
    else cout << res << endl;

    return 0;
}