#include <fstream>

using namespace std;

ifstream fin("grupuri.in");
ofstream fout("grupuri.out");

long long k, n, v[100100], i, g, l, r, m, sol;

bool sePoate(long long x)
{
    long long s = 0;
    for (i = 1; i <= n; i++) {
        if (v[i] < x)
            s += v[i];
        else
            s += x;
    }
    if (s >= k * x)
        return true;
    return false;
}

int main()
{
    fin >> k >> n;
    for (i = 1; i <= n; i++)
        fin >> v[i];
    l = 0;
    r = 100000000000;
    while (l <= r) {
        m = (l + r) / 2;
        if (sePoate(m)) {
            sol = m;
            l = m + 1;
        }
        else
            r = m - 1;
    }
    fout << sol;
    fin.close();
    fout.close();
    return 0;
}