#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(a) a.begin(),a.end()
#define reps(i, a, n) for (int i = (a); i < (int)(n); i++)
#define rep(i, n) reps(i, 0, n)
#define rreps(i, a, n) for (int i = (a); i > (int)(n); i--)
const long long INF = 1e18;
ll myceil(ll a, ll b) {return (a+b-1)/b;}

template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
template<typename T> using vvv = vv<vc<T>>;

template<typename T> inline bool chmax(T &a, T b) { return ((a < b) ? (a = b, true) : (false)); }
template<typename T> inline bool chmin(T &a, T b) { return ((a > b) ? (a = b, true) : (false)); }

#define debug(var) do { cout << #var << " :\n"; view(var); } while(0)
template<typename T>void view(const T& e) {cout << e;}
template<typename T1, typename T2>void view(const pair<T1, T2>& p) {cout << "{" << p.first << ", " << p.second << "}";}
template<typename T>void view(const vc<T>& v) {for (const auto& e : v) {view(e);cout << " ";} cout << endl;}
template<typename T>void view(const vv<T>& vv) {for (const auto& v : vv) {view(v);} cout << endl;}
template<typename T>void view(const set<T>& s) {for (const auto& e : s) {view(e);cout << " ";} cout << endl;}
template<typename T>void view(const multiset<T>& s) {for (const auto& e : s) {view(e);cout << " ";} cout << endl;}
template<typename T>void view(const unordered_set<T>& s) {for (const auto& e : s) {view(e);cout << " ";} cout << endl;}
template<typename T>void view(const unordered_multiset<T>& s) {for (const auto& e : s) {view(e);cout << " ";} cout << endl;}
template<typename T1, typename T2>void view(const map<T1, T2>& mp){for (const auto& e : mp) {view(e);cout << " ";} cout << endl;}


// # pragma GCC target("avx2")
// # pragma GCC optimize("O3")
// # pragma GCC optimize("unroll-loops")


void solve() {
    ll n,m;
    cin >> n >> m;
    map<ll,ll> mp;
    ll a,b;
    rep(i,n) {
        cin >> a >> b;
        mp[(m-a)/b]++;
    }

    ll ct = 0;
    ll ans = 0;

    for (auto x : mp) {
        ct += x.second;
        ans = max(ans,myceil(ct,x.first+1));
    }
    
    cout << ans << endl;
}



int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);

    int t = 1;
    // cin >> t;
    rep(i,t)  solve();

	return 0;
}