#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=0;
    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 = 20000000000000, x;
    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;
    return 0;
}