#include <bits/stdc++.h>

using namespace std;

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

long long n, k, a[100100], st, dr, mid;

int main() {
	in >> k >> n;
	for (int i = 1; i <= n; i++)
		in >> a[i];
	st = 0, dr = (int) 1e12;
	while (st <= dr) {
		mid = st + dr >> 1;
		long long rs = 0;
		for (int i = 1; i <= n; i++)
			rs += min(a[i], mid);
		if (rs >= mid * k)
			st = mid + 1;
		else dr = mid - 1;
	}
	out << dr;
	return 0;
}