#include<bits/stdc++.h> using namespace std; const int N=1e5+10; const int INF=0x3f3f3f3f; int n,p,maxx=-INF,minn=INF; int a[N]; bool check(double mid) { int len=1,p1=p-1; for(int i=2;i<=n;++i) { if(a[i]-a[len]>=mid) { len=i; p1--; } } return p1<=0; } int main() { IOS; cin>>n>>p; for(int i=1;i<=n;++i) { cin>>a[i]; minn=min(minn,a[i]); maxx=max(maxx,a[i]); } sort(a+1,a+n+1); int l=1,r=maxx-minn; while(l<r) { int mid=(l+r+1)>>1; if(check(mid)) { l=mid; } else { r=mid-1; } } cout<<l; return 0; }