#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  while (~scanf("%d%d", &n, &h)) {
    int a[n], b[n], ans = 0;
    for (int i = 0; i < n; i++) scanf("%d%d", &a[i], &b[i]);
    int maxA = 0, maxAindex;
    for (int i = 0; i < n; i++)
      if (a[i] > maxA) maxA = a[i], maxAindex = i;
    for (int i = 0; i < n; i++)
      if (b[i] >= maxA && h > 0 && i != maxAindex) h -= b[i], ans++;
    if (h > 0) h -= b[maxAindex], ans++;
    if (h <= 0) {
      printf("%d\n", ans);
      continue;
    }
    h % a[maxAindex] == 0 ? ans += h / a[maxAindex]
                          : ans = ans + h / a[maxAindex] + 1;
    printf("%d\n", ans);
  }
}
