#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define F first
#define S second
#define mk make_pair
#define pii pair < int , bool >
const int maxn = 2e6 + 100;
const ll inf = 1e18;

int a[maxn] , check[maxn] , k;
pii seg[4 * maxn];
void build(int l = 0 , int r = k + 2 , int id = 1){
	   if (r - l == 1){
			 seg[id].F = check[l];
			 if (seg[id].F)
				    seg[id].S = 1;
			 return;
	   }
	   int mid = (l + r) >> 1;
	   build(l , mid , id << 1 | 0);
	   build(mid , r , id << 1 | 1);
	   seg[id].S = (seg[id << 1 | 0].S && seg[id << 1 | 1].S);
	   return;
}
int get (int l = 0 , int r = k + 2 , int id = 1){
	   if (r - l == 1){
			 if (seg[id].S)
				    return -1;
			 return l;
	   }
	   int mid = (l + r) >> 1;
	   if (!seg[id << 1 | 0].S)
			 return get(l , mid , id << 1 | 0);
	   if (!seg[id << 1 | 1].S)
			 return get(mid , r , id << 1 | 1);
	   return -1;
}
void update(int idx , int x , int l = 0 , int r = k + 2 , int id = 1){
	   if (idx < l || idx >= r)
			 return;
	   if (r - l == 1){
			 seg[id].F += x;
			 if (seg[id].F)
				    seg[id].S = 1;
			 else
				    seg[id].S = 0;
			 return;
	   }
	   int mid = (l + r) >> 1;
	   update(idx , x , l , mid , id << 1 | 0);
	   update(idx , x , mid , r , id << 1 | 1);
	   seg[id].S = (seg[id << 1 | 0].S && seg[id << 1 | 1].S);
	   return;
}
int main() {
	   ll n;
	   cin >> k >> n;
	   check[0] = 1;
	   for (int i = 0; i < k; i++){
			 cin >> a[i];
			 if (a[i] <= k + 1)
				    check[a[i]]++;
	   }
	   build();
	   ll y = -1 , u = 0;
	   bool g = 0;
	   for (int i = k; i <= 2 * k; i++ , u++){
			 int t = get();
			 //cout << "t : " << t << "\n";
			 if (t == k + 1 && !g){
				    a[i] = t;
				    y = i;
				    g = 1;
			 }
			 update(t , 1);
			 update(a[u] , -1);
			 a[i] = t;
	   }
	   if (n <= 2 * k)
			 return cout << a[n - 1] << "\n" , 0;
	   n -= (y - k);
	   n--;
	   ll p = n % (k + 1);
	   int q = (y - k + p);
	   cout << a[q] << "\n";
	   return 0;
}