#include <bits/stdc++.h>
using namespace std;
ifstream fin("grupuri.in");
ofstream fout("grupuri.out");

const int MAXN = 1e5;
long long n, k, i, st, dr, mij, sol, sum;
long long a[MAXN + 1];

int main()
{
    fin >> k >> n;
    for( i = 1; i <= n; i++)
        fin >> a[i];
    //cautam binar solutia intre 0 si MAXN * MAXV grupuri posibile
    st = 0, dr = 1e11;
    while( st <= dr ) {
        mij = (st + dr) / 2;
        sum = 0;
        for( i = 1; i <= n; i++)
            sum += min(a[i], mij);
        if( sum < mij * k )
            dr = mij - 1;
        else {
            sol = mij;
            st = mij + 1;
        }
    }
    fout << sol;
    return 0;
}