#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
// #include<ext/pb_ds/assoc_container.hpp>
// #include<ext/pb_ds/tree_policy.hpp>
// #include<ext/pb_ds/tag_and_trait.hpp>
// using namespace __gnu_pbds;
// #include<boost/multiprecision/cpp_int.hpp>
// namespace multiprecisioninteger = boost::multiprecision;
// using cint=multiprecisioninteger::cpp_int;
using namespace std;
using ll=long long;
#define double long double
using datas=pair<ll,ll>;
using ddatas=pair<double,double>;
using tdata=pair<ll,datas>;
using vec=vector<ll>;
using mat=vector<vec>;
using pvec=vector<datas>;
using pmat=vector<pvec>;
// using llset=tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>;
#define For(i,a,b) for(i=a;i<(ll)b;++i)
#define bFor(i,b,a) for(i=b,--i;i>=(ll)a;--i)
#define rep(i,N) For(i,0,N)
#define rep1(i,N) For(i,1,N)
#define brep(i,N) bFor(i,N,0)
#define brep1(i,N) bFor(i,N,1)
#define all(v) (v).begin(),(v).end()
#define allr(v) (v).rbegin(),(v).rend()
#define vsort(v) sort(all(v))
#define vrsort(v) sort(allr(v))
#define endl "\n"
#define eb emplace_back
#define print(v) cout<<v<<endl
#define printyes cout<<"Yes"<<endl
#define printno cout<<"No"<<endl
#define printYES cout<<"YES"<<endl
#define printNO cout<<"NO"<<endl
#define output(v) do{bool f=0;for(auto outi:v){cout<<(f?" ":"")<<outi;f=1;}cout<<endl;}while(0)
#define matoutput(v) do{for(auto outimat:v)output(outimat);}while(0)
const ll mod=1000000007;
// const ll mod=998244353;
const ll inf=1LL<<60;
const double PI = acos(-1);
const double eps = 1e-9;
template<class T> inline bool chmax(T& a,T b){bool x=a<b;if(x)a=b;return x;} 
template<class T> inline bool chmin(T& a,T b){bool x=a>b;if(x)a=b;return x;} 

void startupcpp(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout<<fixed<<setprecision(15);
}
struct unionfind{
  private:
  int maxN;
  vector<int> par,treesize,maxid,minid;
  public:unionfind(int N) :maxN(N),par(N),treesize(N,1){
    int i;
    for(i=0;i<maxN;++i)par[i]=i;
    maxid=minid=par;
  }
  int root(int x){
    if(par[x]==x)return x;
    int r=root(par[x]);
    if(par[x]!=r){
      treesize[r]+=treesize[x];
      treesize[x]=0;
      par[x]=r;
    }
    return r;
  }
  bool unite(int x,int y){
    int px=root(x);
    int py=root(y);
    if(px!=py){
      par[px]=py;
      treesize[py]+=treesize[px];
      treesize[px]=0;
      maxid[px]=maxid[py]=max(maxid[px],maxid[py]);
      minid[px]=minid[py]=min(minid[px],minid[py]);
    }
    return px!=py;
  }
  void used(int x){
    --treesize[root(x)];
  }
  bool parcheck(int x,int y){
    return root(x)==root(y);
  }
  pair<int,int> I(int x){
    return pair<int,int>(minid[root(x)],maxid[root(x)]+1);
  }
  int size(int x){
    return treesize[root(x)];
  }
  void clear(){
    int i;
    for(i=0;i<maxN;++i){
      par[i]=i;
      treesize[i]=1;
    }
  }
};
template<typename T> struct segtree{
private:
  int N=1;
  T E;
  using func=function<T(T,T)>;
  func f,g;
  vector<T> tree;
public:
  segtree(vector<T>& v,T e,func Merge,func Act):E(e),f(Merge),g(Act){
    int i,K=v.size();
    while(N<K)N<<=1;
    tree.resize(N<<1);
    For(i,N,N+K)tree[i]=v[i-N];
    For(i,N+K,N<<1)tree[i]=E;
    brep1(i,N)tree[i]=f(tree[i<<1],tree[(i<<1)|1]);
  }
  segtree(vector<T>& v,T e,func Merge){*this=segtree(v,e,Merge,Merge);};
  segtree(int N,T e,func F){
    vector<T> res(N,e);
    *this=segtree(res,e,F);
  }
  void action(int i,T a){
    if((i<0)|(i>=N))return;
    i+=N;
    tree[i]=g(tree[i],a);
    while(i>1){
      i>>=1;
      tree[i]=f(tree[i<<1],tree[(i<<1)|1]);
    }
  }
  void input(int i,T a){
    if((i<0)|(i>=N))return;
    tree[i+=N]=a;
    while(i>1){
      i>>=1;
      tree[i]=f(tree[i<<1],tree[(i<<1)|1]);
    }
  }
  T queli(int a,int b){
    if((a>=b)|(a<0)|(b<=0)|(a>=N)|(b>N))return E;
    T l(E),r(E);
    for(a+=N,b+=N;a<b;a>>=1,b>>=1){
      if(a&1)l=f(l,tree[a++]);
      if(b&1)r=f(tree[--b],r);
    }
    return f(l,r);
  }
};

int main(){
  startupcpp();
  ll i,j,N,K,Q,ans=inf;
  cin>>N>>K>>Q;
  unionfind utree(N);
  vec a(N);
  vector<datas> v(N);
  rep(i,N){
    cin>>a[i];
    v[i]=datas(a[i],i);
  }
  segtree<datas> tree(v,datas(inf,inf),[](datas a,datas b){return min(a,b);});
  vrsort(v);
  priority_queue<ll> que;
  for(auto x:v){
    if(x.second&&x.first<=a[x.second-1])utree.unite(x.second,x.second-1);
    if(x.second<N-1&&x.first<=a[x.second+1])utree.unite(x.second,x.second+1);
    if(utree.size(x.second)>=K){
      auto t=utree.I(x.second);
      while(utree.size(x.second)>=K){
        auto push=tree.queli(t.first,t.second);
        que.push(push.first);
        push.first=inf;
        tree.input(push.second,push);
        utree.used(x.second);
      }
      while(que.size()>Q)que.pop();
      if(que.size()==Q){
        chmin(ans,que.top()-x.first);
      }
    }
  }
  print(ans);
}

Measured memory_bytes: 384