#difference of average
N=int(input())
K=int(input())
n=[int(input()) for i in range(N)]
mx=n[0]
mi=n[0]
i=1
while i<N:
    if mx<n[i]:
        mx=n[i]
    if mi>n[i]:
        mi=n[i]
    i+=1
print(mx-mi)