import sys
import math

# Auto-generated code below aims at helping you parse
# the standard input according to the problem statement.

n = int(input())
pi = []
for i in range(n):
    pi.append(int(input()))

pi.sort()
mini = 9999
for i in range(1,n):
    mini = min(mini,abs(pi[i]-pi[i-1]))

print(mini)