#include<stdio.h>
#include<algorithm>
using namespace std;
int P, Q, N, ans;
int w[2020];
int dp[2020][2020];
int prev[2020][2];
void pre(int x,int t)
{
int i;
for(i=1;i<=N&&w[i]-w[1]<x;i++)prev[i][t] = 1;
for(int j=1;i<=N;i++){
while(w[i]-w[j]>=x)j++;
prev[i][t] = j;
}
}
bool chk(int x)
{
pre(x,0), pre(x<<1,1);
int i, j;
dp[0][0] = N+1;
for(i=1;i<=P;i++)dp[i][0] = prev[dp[i-1][0]-1][0];
for(i=1;i<=Q;i++)dp[0][i] = prev[dp[0][i-1]-1][1];
for(i=1;i<=P;i++)
for(j=1;j<=Q;j++)
dp[i][j] = min(prev[dp[i-1][j]-1][0], prev[dp[i][j-1]-1][1]);
return dp[P][Q] <= 1;
}
int main()
{
scanf("%d%d%d",&N,&P,&Q);
if(P+Q >= N)return printf("1")&0;
for(int i=1;i<=N;i++)scanf("%d",w+i);
sort(w+1,w+1+N);
for(int s=1,e=1e9;s<=e;){
int m = (s+e)>>1;
if(chk(m))ans = m, e = m-1;
else s = m+1;
}
printf("%d",ans);
return 0;
}
