#include <bits/stdc++.h> using namespace std; long long n, p, q, a[2005], mini, medi, maxi, far, dp[2005][2005]; long long need(long long idx, long long big, long long w){ if(idx < 0) return 0; if(dp[idx][big] != -1) return dp[idx][big]; dp[idx][big] = INT_MAX; if(big > 0){ far = upper_bound(a, a+n, a[idx]-w-w)-a; far--; dp[idx][big] = min(dp[idx][big], need(far, big-1, w)); } far = upper_bound(a, a+n, a[idx]-w)-a; far--; dp[idx][big] = min(dp[idx][big], (long long) (need(far, big, w)+1)); return dp[idx][big]; } int main(){ cin >> n >> p >> q; if(p+q >= n){ cout << 1; return 0; } for(int i = 0; i < n; i++) cin >> a[i]; sort(a, a+n); mini = 0; maxi = a[n-1]+1; while(mini < maxi){ medi = mini+(maxi-mini)/2; memset(dp, -1, sizeof(dp)); if(need(n-1, q, medi) <= p) maxi = medi; else mini = medi+1; } cout << mini; }