#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, max = 0, num, count = 0;
  long H, a[100001], b[100001];
  cin >> N >> H;
  for (int i = 1; i <= N; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > max) {
      max = a[i];
      num = i;
    }
  }
  for (int i = 1; i <= N; i++) {
    if (b[i] > max) {
      H -= b[i];
      count++;
    }
    if (H <= 0) {
      cout << count << endl;
      return 0;
    }
  }
  int j = 1;
  while (H - j * max > 0) {
    j++;
  }
  cout << count + j << endl;
}
