#include <bits/stdc++.h>
using namespace std;
const int vx[4] = {0, 1, 0, -1};
const int vy[4] = {1, 0, -1, 0};
int n, h;
int a[110000], b[110000];
int main() {
  cin >> n >> h;
  for (int i = (int)0; i < (int)n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  sort(b, b + n);
  reverse(a, a + n);
  reverse(b, b + n);
  int ans = 0;
  int i = 0;
  while (b[i] > a[0] && h > 0) {
    h -= b[i];
    ans++;
    i++;
  }
  ans += (h + a[0] - 1) / a[0];
  cout << ans << endl;
}
