#include <bits/stdc++.h>

using namespace std;

ifstream fin("grupuri.in");
ofstream fout("grupuri.out");
int k, n, a[100002], i, st, m, sum;
long long dr;

int main() {
    fin >> k >> n;
    for(i = 1; i <= n; i++) fin >> a[i], dr += a[i];
    st = 1;
    dr /= k;
    while(st <= dr) {
        m = st + (dr - st) / 2;
        sum = 0;
        for(i = 1; i <= n; i++) sum += min(m, a[i]);
        if(sum >= 1LL * m * k) st = m + 1;
        else dr = m - 1;
    }
    fout << dr;

    return 0;
}