#include <bits/stdc++.h>

using namespace std;
ifstream fin("grupuri.in");
ofstream fout("grupuri.out");
long long v[100001];
int main()
{
    long long n,k,i,aux,suma;
    fin>>k>>n;
    for(i=1;i<=n;i++) {
        fin>>v[i];
    }
    long long st,dr,mijl;
    st=1;
    dr=100000000000;
    while(st<=dr) {
        suma=0;
        mijl=(st+dr)/2;
        for(i=1;i<=n;i++) {
            if(v[i]>mijl) {
                suma+=mijl;
            }
            else{
                suma+=v[i];
            }
        }
        if(suma>=k*mijl) {
            st=mijl+1;
            aux=mijl;
        }
        else
            dr=mijl-1;
    }
    fout<<aux;
    return 0;
}