C++ :

#include<iostream>
#include<algorithm>
using namespace std;
const int N = 100005;
struct person{
	int id,score,power;
};
person a[2*N],win[N],lose[N];

bool comp(const person &x,const person &y){
	if (x.score!=y.score) return x.score>y.score;
	return x.id<y.id;
}

void swiss(int n){
	int i,j,k;
	for (k=i=j=1; k<=n; k++)
		if (a[2*k-1].power>a[2*k].power)
			a[2*k-1].score++,win[i++]=a[2*k-1],lose[j++]=a[2*k];
		else a[2*k].score++,win[i++]=a[2*k],lose[j++]=a[2*k-1];
	for (k=i=j=1; i<=n&&j<=n; k++)
		if (comp(win[i],lose[j])) a[k]=win[i++];
		else a[k]=lose[j++];
	while (i<=n) a[k++]=win[i++];
	while (j<=n) a[k++]=lose[j++];
}

int main(){
	int n,r,q;
	cin>>n>>r>>q;
	for (int i=1; i<=2*n; i++){
		cin>>a[i].score;
		a[i].id=i;
	}
	for (int i=1; i<=2*n; i++) cin>>a[i].power;
	sort(a+1,a+2*n+1,comp);
	for (int i=1; i<=r; i++) swiss(n);
	cout<<a[q].id<<endl;
	return 0;
}