#include <bits/stdc++.h>
using namespace std;
int n, m, mx, s, num, mn = 2e9;
pair<int, int> a[100005];
int main() {
  int i;
  cin >> n >> m;
  for (i = 0; i < n; i++) {
    scanf("%d %d", &a[i].second, &a[i].first);
    mx = max(mx, a[i].second);
  }
  sort(a, a + n);
  for (i = n; i >= 0; i--) {
    s += a[i].first;
    num = (m - s) / mx;
    if ((m - s) % mx > 0) num++;
    num += n - i;
    mn = min(mn, num);
  }
  cout << mn;
  return 0;
}
