#include <iostream>
#include <algorithm>
//by GB Zaleski
using namespace std;
int Uphold,n;
int tab[30000];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> Uphold >> n;
    for (int i=0; i!=n; ++i) cin >> tab[i];
    sort(tab,tab+n);
    int x = 0;
    int y = n-1;
    int result = 0;
    while (x <= y)
    {
        if (tab[x]+tab[y] <= Uphold) ++x;
        y--;
        result++;
    }
    cout << result;
    return 0;
}