Problem:
Score: 400 points

Problem Statement

The Kingdom of Takahashi has N towns, numbered 1 through N.

There is one teleporter in each town. The teleporter in Town i (1 \leq i \leq N) sends you to Town A_i.

Takahashi, the king, loves the positive integer K. The selfish king wonders what town he will be in if he starts at Town 1 and uses a teleporter exactly K times from there.

Help the king by writing a program that answers this question.

Constraints

2 \leq N \leq 2 \times 10^5

1 \leq A_i \leq N

1 \leq K \leq 10^{18}

Input

Input is given from Standard Input in the following format:

N K
A_1 A_2 \dots A_N

Output

Print the integer representing the town the king will be in if he starts at Town 1 and uses a teleporter exactly K times from there.

Sample Input 1

4 5
3 2 4 1

Sample Output 1

4

If we start at Town 1 and use the teleporter 5 times, our travel will be as follows: 1 \to 3 \to 4 \to 1 \to 3 \to 4.

Sample Input 2

6 727202214173249351
6 5 2 5 3 2

Sample Output 2

2

Solution in Julia (1.4.0) (judge verdict: Time Limit Exceeded)

using DataStructures
parseline(str) = parse.(Int, split(str))
function Teleporter()
    N, K = parseline(readline())
    A = parseline(readline())
    route = zeros(Int, N)
    route[1] = A[1]
    pre = 0
    for k in 2:K
        a = A[route[k-1]]
        a in route && (i=findfirst(route.==a);pre=length(route[1:i-1]);route = route[i:k-1]; break)
        route[k] = a
    end
    println(route[(K-pre-1)%length(route)+1])
end
Teleporter()