#include<bits/stdc++.h>
using namespace std;
bool M1;
#define PI 3.14159265358979323846
#define sz(a) (int)a.size()
#define all(x) x.begin(),x.end()
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<'\n'
#define look_time cerr << "TIME : " << clock() * 0.001 << "s" <<'\n'
const int N=1e2+5,lg=30,mod=998244353;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
return u+rd()%(v-u+1);
}
int dx[]={1,0,-1,0,1,1,-1,-1};
int dy[]={0,-1,0,1,1,-1,1,-1};
int node,a[N],p,q;
int dp[N][N][N];
bool M2;
void solve(){
cin >> node >> p >> q;
p=min(p,node);
q=min(q,node);
for(int i=1;i<=node;++i){
cin >> a[i];
}
sort(a+1,a+1+node);
memset(dp,0x3f,sizeof dp);
a[0]=a[1];
// dp[1][0][0]=0;
dp[0][0][0]=0;
for(int i=1;i<=node;++i){
for(int k=0;k<=q;++k){
for(int l=0;l<=p;++l){
for(int j=1;j<=i;++j){
int val=a[i]-a[j]+1;
if(k>0){
// cout <<i<<" "<<j<<" "<<val<<'\n';
dp[i][k][l]=min(dp[i][k][l],max(dp[j-1][k-1][l],val/2+val%2));
// if(i==4&&k==0&&l==2)
// cout <<j<<" "<<k<<" "<<l<<" "<<val/2+val%2<<" "<<dp[j-1][k-1][l]<<'\n';
}
if(l>0){
dp[i][k][l]=min(dp[i][k][l],max(dp[j-1][k][l-1],val));
// if(i==3&&k==0&&l==1)
// cout <<j<<" "<<k<<" "<<l<<" "<<val<<" "<<dp[j-1][k][l-1]<<'\n';
}
}
}
}
}
// cout <<dp[11][2][2];
// for(int i=1;i<=node;++i)cout << a[i]<<" ";
int ans=1e9;
for(int i=0;i<=q;++i){
for(int j=0;j<=p;++j){
ans=min(ans,dp[node][i][j]);
// cout <<dp[node][i][j]<<" ";
}
// cout<<'\n';
}
cout << ans;
}
main()
{
srand(time(0));
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
#define task "paleta"
if(fopen(task".inp","r")){
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
int t=1;
solve();cout<<'\n';
look_memory;
look_time;
}
