let n = readLine()!.split(separator: " ").map{Int($0)!}
var a = readLine()!.split(separator: " ").map{Int($0)!}
a += [0]
for i in 0..<n[0]{
    a[n[0]] ^= a[i]
}
print(a[n[1]%(n[0]+1)-1])