#include <bits/stdc++.h> using namespace std; #define name "ojuz" #define MAXN 2003 #define pb push_back #define pf push_front #define ll long long #define ii pair<int, int> #define fs first #define sc second #define ill pair<int, ll> #define lli pair<ll, int> #define llll pair<ll, ll> #define all(v) v.begin(),v.end() #define uni(v) v.erase(unique(all(v)),v.end()) #define bit(n,i) (((n)>>(i))&1) #define FOR(i,a,b) for (int i=(a),_b=(b); i<=_b; i++) #define FORD(i,a,b) for (int i=(a),_b=(b); i>=_b; i--) #define MASK(i) (1LL<<(i)) const int INF=1e9; const int MOD=1e9+7; void add(int &u, int v){ u+=v; if (u>=MOD) u-=MOD; } void sub(int &u, int v){ u-=v; if (u<0) u+=MOD; } void minimize(int &u, int v){ u=min(u,v); } void maximize(int &u, int v){ u=max(u,v); } long long Rand(long long l, long long r){ ll tmp=0; FOR(i,1,4) tmp=((tmp<<15)^(((1<<15)-1)&rand())); return l+tmp%(r-l+1); } int n,p,q; int a[MAXN]; int f[MAXN],g[MAXN]; int dp[MAXN][MAXN]; bool check(int w){ f[1]=1; FOR(i,2,n){ f[i]=f[i-1]; while (a[i]-a[f[i]]>=w) ++f[i]; } g[1]=1; FOR(i,2,n){ g[i]=g[i-1]; while (a[i]-a[g[i]]>=2*w) ++g[i]; } FOR(i,0,n) FOR(j,0,p) dp[i][j]=INF; dp[0][0]=0; FOR(i,1,n){ FOR(j,0,p){ if (j>=1) minimize(dp[i][j],dp[f[i]-1][j-1]); minimize(dp[i][j],dp[g[i]-1][j]+1); } } FOR(j,0,p){ if (dp[n][j]<=q) return 1; } return 0; } int main() { ios::sync_with_stdio(0), cin.tie(0), cout.tie(0); cin>>n>>p>>q; FOR(i,1,n) cin>>a[i]; if (p+q>=n){ cout<<1; return 0; } sort(a+1,a+n+1); int l=1,r=INF,res=-1; while (l<=r){ int mid=(l+r)/2; if (check(mid)){ r=mid-1; res=mid; } else l=mid+1; } cout<<res; return 0; }