#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long int h;
  long long int a[100000 + 5], b[100000 + 5];
  while (cin >> n >> h) {
    for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
    sort(b, b + n);
    int j;
    long long int max = 0;
    for (int i = 0; i < n; i++)
      if (max < a[i]) {
        max = a[i];
        j = i;
      }
    int cnt = 0;
    int flag = 0;
    for (int i = (n - 1); i >= 0; i--) {
      if (i == j) continue;
      if (b[i] > max) {
        h = h - b[i];
        cnt++;
        if (h <= 0) flag = 1;
      } else
        break;
      if (flag) break;
    }
    if (flag)
      cout << cnt << endl;
    else {
      int kk;
      if (h % max == 0)
        kk = h / max;
      else
        kk = (int)(h / max) + 1;
      cnt = cnt + kk;
      cout << cnt << endl;
    }
  }
  return 0;
}
