import sequtils,strutils,algorithm
var
    N = stdin.readline.parseInt
    X = stdin.readline.split.map(parseInt)

X.sort(system.cmp)
var ans = 10_000_000
for i,x in X:
    if i == 0:
        continue
    var d = x - X[i - 1]
    if d == 0:
        continue
    ans = min(d, ans)

if ans == 10_000_000:
    echo 0
else:
    echo ans