import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**15
mod = 10**9+7

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)


def main():
    n,k,q = LI()
    a = LI()
    bb = sorted([[a[i],i] for i in range(n)])
    b = list(map(lambda x: x[1], bb))
    sa = sorted(a)
    r = sa[q-1] - sa[0]
    # print(r)
    # print(sorted([[a[i],i] for i in range(n)]))
    for i in range(1,n):
        if q-1+i > n-1 or sa[i] == sa[i-1]:
            continue
        t = sa[q-1+i] - sa[i]
        # print(i, t)
        if t >= r:
            continue
        c = sorted([_[1] for _ in bb if _[0] <= sa[i]]) + [n]
        e = -1
        g = 0
        for d in c:
            if d - e < 2:
                e = d
                continue
            f = d - e - 1
            if f > k:
                g += f - k
            e = d
        # print('g',g,q)
        if g >= q:
            r = t


    return r




print(main())

