using namespace std;
#include<iostream>
#include<fstream>

int k, n, v[100001];
int s;

int cautbin(int x, int v[]) {
    int st = 1, dr = n;
    int rasp = 0;

    while (st <= dr) {
        int mid = (st+dr)/2;

        if (v[mid] >= x) {
            rasp = mid;
            dr = mid-1;
        } else {
            st = mid + 1;
        }
    }

    return rasp;
}

int main() {

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

    fin >> k >> n;

    for (int i = 1; i<=n; i++) {
        fin >> v[i];
    }

    int inceput = cautbin(k, v);

    for (int i = 1; i<inceput; i++) {
        s += v[i];
    }

    s += k*(n-inceput+1);

    s /= k;

    fout << s;


    fin.close();
    fout.close();

    return 0;
}