#include <fstream>

using namespace std;

ifstream cin("grupuri.in");
ofstream cout("grupuri.out");

int v[1000001],k,n;
int grupuri(int x){
    int i;
    long long s=0;
    for(i=1;i<=n;i++)
        s+=min(x,v[i]);
    if(s>=(long long)x*k)
        return 1;
    else
        return 0;
};

int main()
{
    int i;
    long long mij,st,dr,elem=0;
    cin>>k>>n;
    for(i=1;i<=n;i++)
        cin>>v[i];
    st=0;dr=100000000000;
    while(st<=dr){
        mij=(st+dr)/2;
        if(grupuri(mij)==0)
            dr=mij-1;
        else{
            elem=mij;
            st=mij+1;
        }
    }
    cout<<elem;
    return 0;
}