#include <bits/stdc++.h>
using namespace std;
#define sz(x) (int) (x).size()
#define all(x) (x).begin(), (x).end()
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
typedef long long lint;
typedef pair<lint,lint> ii;
int arr[400005];
int target[400005];
int n, R;
int me;
inline int bruhmod(int x){
int res = x%n;
if(res <= 0) res += n;
return res;
}
///for strong
vector<int> candidates[800005];
///for weak
int taken[200005];
inline int solve(int s){
//return debuggingstuff[s];
target[me] = s;
for(int i = 1;i <= 2*n;i++){
int newi = i + (i >= 2*s);
target[arr[i]] = (newi+1)/2;
}
if(me >= n+2){ ///weak
fill(taken,taken+n+1,0);
for(int i = me+1;i <= 2*n;i++) taken[target[i]]++;
int cnt = 0;
for(int i = n;i >= 2;i--){
cnt += taken[i]; taken[i] = 0;
if(cnt > 0){
taken[i] = 1;
cnt--;
}
}
cnt += taken[1];
for(int i = n;i >= 2;i--){
cnt += taken[i]; taken[i] = 0;
if(cnt > 0){
taken[i] = 1;
cnt--;
}
}
bool looparound = false;
int pos = target[me];
while(true){
if(pos == 1){
pos = n;
looparound = true;
}
if(taken[pos] == 0) return pos - (looparound * n);
pos--;
}
}
else{ ///strong
for(int i = 1;i <= 3*n;i++) candidates[i].clear();
for(int i = 1;i <= 2*n;i++){
candidates[target[i]].push_back((i > me) + (i >= me));
}
if(candidates[1][0] < candidates[1][1]) swap(candidates[1][0], candidates[1][1]);
int winner = candidates[1][1]; candidates[1].pop_back();
int looparounds = 0;
vector<int> choices = {0,0,0};
for(int turn = 1;turn <= 3*n;turn++){
for(int x : candidates[turn]){
choices[x]++;
}
int t = 0;
while(choices[t] == 0) t++;
choices[t]--;
if(turn >= 2*n and t == 1){
int turnsleft = R-turn+1;
looparounds += (turnsleft + n - 1) / n;
turnsleft %= n;
int res = (1-turnsleft+n) % n;
if(res == 0) res = n;
return res - n * looparounds;
}
if(t < winner) swap(t, winner);
if(t == 1) looparounds++;
if(turn < 2*n) candidates[turn+n].push_back(t);
}
}
assert(false);
return -4;
}
inline int bsta(int x){ ///find last position <= x
int low = 0, high = n+1;
while(low < high-1){
int mid = (low+high)/2;
if(solve(mid) <= x) low = mid;
else high = mid;
}
return low;
}
int bestPos = -1;
int bestVal = 1;
inline void consider(int pos){
int val = solve(pos);
int valmod = bruhmod(val);
if(valmod < bestVal){
bestVal = valmod;
bestPos = pos;
}
if(valmod == bestVal and bestPos < pos){
bestVal = valmod;
bestPos = pos;
}
}
signed main(){
//freopen("i.txt","r",stdin);
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> R;
cin >> me;
//for(int i = 1;i <= n;i++) cin >> debuggingstuff[i];
if(me == 1){
cout << n;
return 0;
}
for(int i = 1;i <= 2*n-1;i++) cin >> arr[i];
//solve(1); return 0;
//for(int i = 1;i <= n;i++) show(solve(i));
bestVal = n+1;
int small = solve(1);
consider(1); consider(n);
int pos = bsta(small);
consider(pos);
small += (n - bruhmod(small));
for(int x = 0;x < 1;x++){
int pos = bsta(small);
if(pos >= n) break;
pos++;
int val = solve(pos);
pos = bsta(val);
consider(pos);
small += n;
}
cout << bestPos;
}
