#include<cstdio>
#include<algorithm>

using namespace std;

const int N = 2005;
int n, k, q, a[N], ans = 1e9+5, t[N], b[N], c[N];

void cal(int mn){
    int l = 1, r = 1;
    b[0] = 0;
    while(l <= n){
        c[0] = 0;
        while(a[l] < mn && l <= n)  l++;
        r = l;
        while(a[r] >= mn && r <= n) r++;
        for(int i = l; i < r && i <= n; i++)
            c[++c[0]] = a[i];
        if(c[0] >= k){
            sort(c+1, c+c[0]+1);
            for(int i = 1; i <= c[0] - k + 1; i++)
                b[++b[0]] = c[i];
        }
        l = r;
    }
    sort(b+1, b+b[0]+1);
    if(b[0] >= q)   ans = min(ans, b[q] - b[1]);
}

int main(){
    scanf("%d%d%d", &n, &k, &q);
    for(int i = 1; i <= n; i++){
        scanf("%d", &a[i]);
        t[i] = a[i];
    }
    sort(t+1, t+n+1);
    for(int i = 1; i <= n; i++)
        cal(t[i]);
    printf("%d\n", ans);
    return 0;
}