import sys
from collections import defaultdict

try:
    import mydebug

    def dprint(*objects):
        print(*objects)
except:
    def dprint(*objects, sep='', end='\n'): pass

n = int(input())
k = int(input())
l = []
for i in range(n):
    l.append(int(input()))
l.sort()
print(l[-1] - l[0])