#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
struct node {
  long long a, b;
} a[100001];
bool cmp(node a, node b) { return a.b > b.b; }
int main() {
  ios::sync_with_stdio(false);
  long long n, h, maxv = 0;
  cin >> n >> h;
  long long s = 0;
  for (long long i = 1; i <= n; i++)
    cin >> a[i].a >> a[i].b, s += (long long)a[i].b, maxv = max(maxv, a[i].a);
  sort(a + 1, a + n + 1, cmp);
  if (s >= h) {
    s = 0;
    int i;
    for (i = 1; i <= n; i++) {
      s += (long long)a[i].b;
      if (s >= h) break;
    }
    cout << i;
    return 0;
  }
  long long tot = 0;
  for (long long i = 1; i <= n; i++)
    if (a[i].b > maxv)
      h -= a[i].b, tot++;
    else
      break;
  if (h % maxv == 0)
    cout << h / maxv + tot;
  else
    cout << h / maxv + 1 + tot;
}
