#include <bits/stdc++.h>
using namespace std;
int a[100005], b[100005];
int main() {
  int n, total;
  scanf("%d%d", &n, &total);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &a[i], &b[i]);
  }
  sort(a, a + n);
  sort(b, b + n);
  int pos = upper_bound(b, b + n, a[n - 1]) - b;
  int pos2 = n - 1;
  int ans = 0;
  while (total > 0 && pos2 >= pos) {
    total -= b[pos2];
    pos2--;
    ans++;
  }
  int cnt = ceil(total * 1.0 / a[n - 1]);
  printf("%d\n", ans + cnt);
  return 0;
}
