// Slower C++ solution:
#include<bits/stdc++.h>

#include<vector>

#include<queue>

#include<stack>

#include<string>

#define INF 0x3f3f3f3f

using namespace std;

inline int read(){

    int w=0,f=1;

    char ch=getchar();

    while(ch<'0'||ch>'9'){

        if(ch=='-')f=-1;

        ch=getchar();

    }

    while(ch>='0'&&ch<='9'){

        w=(w<<3)+(w<<1)+ch-48;

        ch=getchar();

    }

    return w*f;

}

int n,m,q,a[200010],b[200010],ans,vec[20010];

priority_queue<int> pq;

inline void work(){

    while(!pq.empty()){

        if(pq.size()>=m){

            vec[0]++;vec[vec[0]]=-pq.top();

        }

        pq.pop();

    }

}

signed main(){

    n=read();m=read();q=read();ans=INF;

    for(int i=1;i<=n;i++)a[i]=read();

    for(int i=1;i<=n;i++){

        int now=a[i];

        for(int j=1;j<=n;j++){

            if(a[j]>=now) pq.push(-a[j]);

            else work();

        }

        work();

        if(vec[0]>=1){

            sort(vec+1,vec+vec[0]+1);

        }

        if(vec[0]>=q&&vec[1]==now){

            ans=min(ans,vec[q]-now);

        }

        memset(vec,0,sizeof(vec));

    }

    cout<<ans<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 1.178413587051029x):
#include <cstdio>

#include <set>

#include <iostream>

#include <cmath>

#include <cstdlib>

#include <algorithm>

#include <cstring>

#include <queue>

#include <map>

#include<numeric>

#include <list>

#define fo(a, b, c) for (register int a = b; a <= c; ++a)

 

namespace IO

{

    inline char gc()

    {

        static char s[1<<20|1]={0},*p1=s,*p2=s;

        return (p1==p2)&&(p2=(p1=s)+fread(s,1,1<<20,stdin),p1==p2)?EOF:*(p1++);

    }

//	inline char gc() { return getchar(); }

	inline long long read()

	{

		long long ret=0;bool flag=0;char c=gc();

		while ((c<'0')|(c>'9')) flag ^= !(c^'-'),c=gc();

		while ((c>='0')&(c<='9')) ret=(ret<<1)+(ret<<3)+(c^'0'),c=gc();

		return flag?-ret:ret;

 	}

 	char OutputAns[1<<20|1],*OutputCur = OutputAns;

 	inline void output()

 	{

 		OutputCur -= fwrite(OutputAns,1,OutputCur - OutputAns,stdout);

	}

	inline void print(long long ans)

	{

		char s[20]={0};

		if (OutputCur - OutputAns + sprintf(s,"I64d",ans) >> 20) output();

		OutputCur += sprintf(OutputCur,"%I64d",ans);

	}

	inline void printc(char c)

	{

		if (OutputCur - OutputAns + 1 >> 20) output();

		*(OutputCur++) = c;

	}

}

 

using IO::read;

using IO::print;

using IO::printc;

using IO::output;

 

using namespace std;

 

typedef long long int64;

 

const int M = 2e3 + 11;

 

int lim, n, q, ans = 2e9;



int A[M], R[M], Ok[M], C[M];



inline void Input()

{

	n = read(), lim = read(), q = read();

	for (int i = 1;i <= n; ++i)

		A[i] = R[i] = read();

	std::sort(R + 1, R + 1 + n);

}



inline void Solve(int Min)

{

	Ok[0] = 0;

	int l = 1, r = 1;

	while (l <= n)

	{

		C[0] = 0;

		while (A[l] < Min && l <= n) ++l;

		r = l;

		while (A[r] >= Min && r <= n) ++r;

		if (r - l < lim) goto end;

		for (int i = l;i < r; ++i)

			C[++C[0]] = A[i];

		std::sort(C + 1, C + 1 + C[0]);

		for (int i = 1;i <= C[0] - lim + 1; ++i)

			Ok[++Ok[0]] = C[i];

		end:; l = r;

	}

	if (Ok[0] < q) return ;

	std::sort(Ok + 1, Ok + 1 + Ok[0]);

	ans = std::min(ans, Ok[q] - Ok[1]);

}



int main(void)

{

	Input();

	for (int i = 1;i <= n - lim + 1; ++i)

		Solve(R[i]);

	printf("%d\n", ans);

	return 0;

}