# include <bits/stdc++.h>

using namespace std;

const int Nmax = 100000 + 5;

long long k, n, x, S, v[Nmax];

int main ()
{
    freopen("grupuri.in", "r", stdin);
    freopen("grupuri.out", "w", stdout);

    scanf("%lld %lld\n", &k, &n);

    for (int i = 1; i <= n; ++i) {
        scanf("%lld ", &v[i]);
        S += v[i];
    }

    while (S / k < v[n])
        S -= v[n], --n, --k;

    printf("%lld\n", S / k);

    return 0;
}