#include <iostream>
#include <fstream>
#include <climits>



using namespace std;
ifstream fin("grupuri.in");
ofstream fout("grupuri.out");



int main()
{
    int n,k;
    fin>>k>>n;
    int v[n+1];
    long long s=0;
    long long sum=0;
    for(int i=1; i<=n; i++)
    {
        fin>>v[i];
        sum+=v[i];
    }

    int st=1;
    int dr=sum;
    while(st<=dr)
    {
        int m=(st+dr)/2;
        s=0;
        for(int i=1; i<=n; i++)
        {
            s+=min(m,v[i]);
        }
        if(s<m*k*1LL)
        {
            dr=m-1;
        }
        else
        {
            st=m+1;
        }
    }

    fout<<dr;

    return 0;
}