#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream f("grupuri.in");
ofstream g("grupuri.out");
int n, k, v[100005], st, dr, out;
long long sum, mid, mx;

int check(){
sum=0;
for(int i=n; i>0; --i)
    sum+=min(mid, (long long)v[i]);
if(sum>=mid*k) return 1;
return 0;
}


int bin_src(){
st=1, dr=mx/k;
while(st<=dr){
    mid=(st+dr)/2;
    if(check())
        out=mid, st=mid+1;
    else
        dr=mid-1;
}


}

int main()
{
f>>k>>n;
for(int i=1; i<=n; ++i)
    f>>v[i], mx+=v[i];
bin_src();
g<<out;



    return 0;
}