let N = Int(readLine()!)
var X = readLine()?.split(separator: " ").map{Int($0)!}
var S:Set = Set<Int>(X!)
if S.count == 1{
    print(0)
}else{
    X = Array(S).sorted()
    var L = [Int]()

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