let N = Int(readLine()!)
var X = readLine()?.split(separator: " ").map{Int($0)!}
var S:Set = Set<Int>(X!)
X = Array(S).sorted()
var L = [Int]()

for i in 0...X!.count - 2{
    L += [X![i + 1] - X![i]]
}
print(L.min()!)