#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int main(){
	int n;
	ll m;
	cin>>n>>m;
	vector<ll> a(n),b(n);
	for(int i=0;i<n;i++)cin>>a[i]>>b[i];
	ll l=0,r=n;
	while(l+1<r){
		ll c=(l+r)/2;
		vector<ll> v(n);
		for(int i=0;i<n;i++){
			v[i]=(m-a[i])/b[i];
		}
		ranges::sort(v);
		bool ok=true;
		for(int i=0;i<n;i++){
			if(v[i]<i/c)ok=false;
		}
		if(ok)r=c;
		else l=c;
	}
	cout<<r<<endl;
}