Sobrinhos.cpp

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;

int v[maxn];

int32_t main(){
	int n, k; cin >> n >> k;
	
	for(int i = 1; i <= n; i++){
		int a, b; cin >> a >> b;
		v[i] = a%b;
	}

	sort(v+1, v+n+1);
	cout << v[k] << '\n';
}