#include <bits/stdc++.h>
using namespace std;
const int maxInt = 1e9 * 2;
const long long int maxLong = 1e18 * 2;
vector<long long int> one, two;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  ;
  long long int n, t;
  cin >> n >> t;
  long long int ans = 0;
  long long int mx = -1;
  for (int i = 0; i < n; i++) {
    long long int x, y;
    cin >> x >> y;
    mx = max(x, mx);
    one.push_back(x);
    two.push_back(y);
  }
  sort(two.begin(), two.end());
  reverse(two.begin(), two.end());
  long long int i = 0;
  long long int tot = 0;
  while (two[i] > mx && i < n) {
    ans++;
    tot += two[i];
    if (tot >= t) {
      break;
    }
    i++;
  }
  if (tot < t) {
    long long int rem = t - tot;
    ans += (rem / mx + (rem % mx));
  }
  cout << ans;
}
