#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,m,a[300005];
bool check(ll x){
	ll cnt = 0;
	for(int i = 1;i <= n;i++){
		cnt += a[i] / x;
		if(a[i] % x > 0) cnt += 1;
	}
	return cnt <= n;
}
int main(){
	cin >> n >> m;
	ll l = 1,r = 0,mid;
	for(int i = 1;i <= m;i++){
		cin >> a[i];
		r = max(r,a[i]);
	}
	while(l + 1 < r){
		mid = (l + r) / 2;
		if(check(mid))
			r = mid;
		else
			l = mid;
	}
	cout << r << endl;
   return 0;
}