#include <fstream>
using namespace std;
ifstream cin("grupuri.in");
ofstream cout("grupuri.out");

int n, k, i, v[100001];
long long s;

int caut(int n, int k, long long s)
{
    if(!k)
        return 0;
    if(v[n]<=s/k)
        return s/k;
    return caut(n-1, k-1, s-v[n]);
}
int main()
{
    cin>>k>>n;
    for(i=1; i<=n; i++)
    {
        cin>>v[i];
        s+=v[i];
    }
    cout<<caut(n,k,s);
    return 0;
}