#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int n,m,a[N],l,r,ans;
bool check(int mid){
	int sum=1,l=a[1];
	for(int i=2;i<=n;i++){
		if(a[i]>=l+mid){
			sum++;
			l=a[i];
		}
	}
	return sum>=m;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	sort(a+1,a+n+1);
	l=1;
	r=a[n];
	while(l<=r){
		int mid=l+r>>1;
		if(check(mid)){
			ans=mid;
			l=mid+1;
		}else{
			r=mid-1;
		}
	}
	cout<<ans;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int n, m;
int a[N], l, r, mid, ans;
bool check(int mid){
	int sum = 1;
	int last = a[1];
	for(int i = 2 ; i <= n ; i++){
		if(a[i] >= last + mid){
			sum++;
			last = a[i];
		}
	}
	return sum >= m;
}
int main(){
	cin >> n >> m;
	for(int i = 1 ; i <= n ; i++) cin >> a[i];
	sort(a + 1 , a + n + 1);
	l = 1;
	r = a[n];
	while(l <= r){
		int mid = l + r >> 1;
		if(check(mid)){
			ans = mid;
			l = mid + 1;
		}
		else r = mid - 1;
	}
	cout << ans << endl;
	return 0;
}

#include<iostream> #include<algorithm> #include<iomanip> #include<cstring> #include<string> #include<cmath> #include<queue> #include<set> using namespace std; const int N=1e5+10; const int INF=0x3f3f3f3f; int n,m,a[N],l,r,ans; bool check(int mid) { int sum=1,last=a[1]; for(int i=2;i<=n;i++) { if(a[i]-last>=mid) { sum++; last=a[i]; } } return sum>=m; } int main(){ cin>>n>>m; for(int i=1;i<=n;i++) cin>>a[i]; sort(a+1,a+n+1); l=1,r=a[n]; while(l<=r) { int mid=l+r>>1; if(check(mid)) { ans=mid; l=mid+1; } else r=mid-1; } cout<<ans; return 0; }