#include<bits/stdc++.h>
using namespace std;
int n,k,q;
int a[2009],b[2009];
int main(){
    cin >> n>>k>>q;
    for(int i = 1;  i <= n; i++){
        cin >> a[i];
    }
    int ans = 1e9;
    for(int i = 1; i <= n; i++){
        int l = 0, x = a[i];
        vector<int> VV;
        for(int j = 1; j <= n+1; j++){
            if(a[j] < x || j == n+1){
                vector<int> V;

                for(int i = l +1; i < j; i ++) {
                    V.push_back(a[i]);
                }
                 l = j;
                if(!V.size()) continue;
                sort(V.begin(),V.end());
                for(int i = 0; i < (int)V.size() - k + 1; i++)
                    VV.push_back(V[i]);

            }
        }
        sort(VV.begin(), VV.end());
        if(VV.size() < q) continue;
        ans = min(ans , VV[q-1]-VV[0]);
    }
    cout<<ans<<endl;

}

