#include <bits/stdc++.h> using namespace std; #define print(l) for(auto i:l) cout<<i<<" ";cout<<endl; #define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i]; #define int long long #define pb push_back #define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> #define all(l) l.begin(),l.end() #define pii pair<int,int> #define fi first #define se second const int M = 1e9+7; const int inf = 1e18; int bp(int x, int y, int p){ int res = 1; x = x % p; while (y > 0) { if (y & 1) res = (res * x) % p; y = y >> 1; x = (x * x) % p; } return res; } int MI(int n, int p){ return bp(n, p - 2, p); } int mul(int x,int y, int p){ return x * 1ull * y % p; } int di(int x,int y, int p){ return mul(x, MI(y, p), p); } int n , m , k , q ,p; void solve(int testcase_number){ cin>>n>>p>>q; input(int,a,n); if(p+q >= n){ cout<<1<<endl; return; } sort(all(a)); // print(a); a.pb(inf); int l =0 ; int r = 1e9+10; while(r-l > 1){ int m = (l+r)/2; int f = 1; vector<vector<int>>dp(n+1,vector<int>(p+1,0)); dp[0][0] = 0; for(int i = 1;i<=n;i++){ int lo = 0; int hi = 0; while( a[i-1]-a[lo] >= m ){ lo++; } while(a[i-1]-a[hi] >=2*m){ hi++; } for(int j = 0;j<=p;j++){ dp[i][j] = dp[hi][j]+1; if(j != 0){ dp[i][j] = min(dp[i][j],dp[lo][j-1]); } } } if(dp[n][p] <= q){ r = m; } else{ l= m; } } cout<<r<<endl; } signed main(){ ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE cin.tie(0), cout.tie(0); cout << fixed<<setprecision(9); int t = 1; // cin>>t; for(int i = 1;i<=t;i++){ solve(i); } }