#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long LL;
struct X{
	LL A;
	LL B;
};
bool Comp(X&l,X&r){
	if (l.A<r.A){
		return true;
	}else if (l.A==r.A){
		return l.B<r.B;
	}
	return false;
}
int main(int argc, char* argv[])
{
	LL N,K,i;
	cin>>N>>K;
	vector<X> AB(N);
	LL MaxV=0;
	LL MinV=10e10;
	for (i=0;i<N;i++){
		cin>>AB[i].A>>AB[i].B;
		if (MinV>AB[i].A){
			MinV=AB[i].A;
		}
		if (MaxV<AB[i].B){
			MaxV=AB[i].B;
		}
	}
	sort(AB.begin(),AB.end(),Comp);
	LL k=0;
	LL M=MinV;
	LL j=0;
	while (MinV<=MaxV){
		for (i=j;i<N;i++){
			if (M<AB[i].A){
				break;
			}
			if (M<=AB[i].B){
				k++;
			}
			if (k==K){
				cout<<M<<endl;
				return 0;
			}
		}
		M++;
		if (M>AB[j].B){
			j++;
		}
	}
	return 0;
}