/*
int      %o/%lo(八进制) %d/%i/%ld/%li(十进制) %x/%lx(十六进制)[如标名为o/lo/d/i/lo/li/x/lx即输出为八进制/十进制/十六进制]
longlong %lld
float    %f/%e
double   %lf/%le
char     %c
char[]   %s
'a'=97
'z'=122
'A'=65
'Z'=90
'0'=48
'9'=57
*/
#include <iostream>
#include <iomanip>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <ctime>
#include <limits>
#include <assert.h>
#include <stdlib.h>
using namespace std;
#define LL long long
#define ull unsigned long long
const int N=1e5+10;
const int INF=0x3f3f3f3f;
const double pi=3.1416;
int n,m,a[N],l,r,ans;
bool check(int mid){
	int sum=1;
	int last=a[1];
	for(int i=2;i<=n;i++){
		if(last+mid<=a[i]){
			last=a[i];
			sum++;
		}
	}
	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]-a[1];
	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<stack>

#include<queue>

#include<cstring>

#include<cmath>

#include<algorithm>

using namespace std;

const int N = 1e6 +10;

const int INF=0x3f3f3f;

int ans,l = 1,r,L,n,k,a[N];

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 >= k;

} int main(){

cin>>n>>k;

for(int i = 1;i<=n;i++)

cin>>a[i];

sort(a+1,a+n+1);

r = a[n] - a[1];

while(l<=r){

int mid = l + r >>1;

if(check(mid)){

ans = mid;

l = mid + 1;

}

else

r = mid - 1;

}

cout<<ans;

}

#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; }