#!/usr/bin/env python3
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


# %%
N, *Y = map(int, read().split())
Y.sort()

# %%
INF = 10**18
segments = [INF] + [y - x for x, y in zip(Y, Y[1:])] + [INF]


# %%
dp = 0, 0
for x in segments:
    dp = dp[1], min(dp) + x

# %%
answer = min(dp)
print(answer)