#include <fstream>

using namespace std;
ifstream cin("grupuri.in");
ofstream cout("grupuri.out");
int v[100001];
#define MAXIM 100000000000
int main()
{
    long long n,k,st,dr,g,s,rez,i;
    cin>>k>>n;
    for(i=1;i<=n;i++)
        cin>>v[i];
    st=1;
    dr=MAXIM;
    while(st<=dr)
    {
        s=0;
        g=(st+dr)/2;
        for(i=1;i<=n;i++)
            s+=min((long long)v[i],g);
        if(s<k*g)
            dr=g-1;
        else
        {
            rez=g;
            st=g+1;
        }
    }
    cout<<rez;
    return 0;
}