#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  map<int, int> mp;
  set<int, greater<int> > st;
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    st.insert(a);
    st.insert(b);
    mp[a] = 1;
  }
  int ans = 0;
  int sum = 0;
  for (auto it = st.begin(); it != st.end(); it++) {
    int val = *it;
    if (mp[val] == 1) {
      ans += (k - sum) / val;
      break;
    }
    sum += val;
    ans++;
  }
  cout << ans << endl;
}
