#include <cstdio>
#include <algorithm>
#include <iostream>
using namespace std;
long long int v;
int xx=0;
long long int a[1000001];
int n;
int ans=0;
int main()
{
    int i;
    freopen("jiahao1.in","r",stdin);
    freopen("jiahao1.out","w",stdout);
    scanf("%lld%d",&v,&n);
    for(i=1;i<=n;i++)
        scanf("%lld",&a[i]);

    sort(a+1,a+1+n);
    for(i=1;i<=n;i++)
    {
        if(a[i]>=v)break;
        if(a[i]%2==1)
        {
            if(xx==0)
            {
                v+=((a[i]/2)+1);
                xx++;
            }
            else
            {
                v+=(a[i]/2);
                xx=0;
            }
        }
        else if(a[i]%2==0)v+=(a[i]/2);
        ans++;
    }
    printf("%d",ans);
    return 0;
}