#include <bits/stdc++.h>

using namespace std;

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

int main()
{
    int N,K;
    uint64_t s=0;
    f>>K>>N;
    vector<int> V(N+1);
    for(int i=1;i<=N;i++)
        f>>V[i], s+=V[i];
    for(int l=1,r=s/K,m;l<=r;s=0)
    {
        m=(l+r)/2;
        for(int i=1;i<=N;s+=min(m,V[i++]));
        if(s>=K*m) l=m+1;
        else r=m-1;
        if(l>r) g<<r;
    }
    return 0;
}