#include<iostream>
#include<fstream>
#include<climits>
using namespace std;
long long i,k,n,mij, rez, v[100001];
long long calc(long long grupe)
{
    long long s;
    for(long long i=1;i<=n;i++)
    {
        s += min(v[i],grupe);
    }
    return s;
}
int main()
{
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);
    cin>>k>>n;
    for(long long i=1;i>=n;i++)
    {
        cin>>v[i];
    }
    long long st=1;
    long long dr= LLONG_MAX-1000;
    while(st<dr)
    {
        mij=(st+dr)/2;
        long long
         x= calc(mij);
        if(x<mij*k)
        {
            dr=mij-1;
        }
        else if(x>=mij*k)
        {
            rez=mij;
            st=mij+1;
        }
        else st=mij+1;
    }
    cout<<rez;
}