#include <bits/stdc++.h>
using namespace std;
template <class A, class B>
inline bool chmax(A &a, B b) {
  return b > a ? a = b, 1 : 0;
}
template <class A, class B>
inline bool chmin(A &a, B b) {
  return b < a ? a = b, 1 : 0;
}
inline bool inside(int y, int x, int H, int W) {
  return (y >= 0 && x >= 0 && y < H && x < W);
}
const int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
const int dy[] = {0, 1, 0, -1, -1, 1, 1, -1};
signed main() {
  cin.tie(0), ios::sync_with_stdio(false);
  int N, H;
  int a;
  int b[100005];
  int maxv = -1;
  cin >> N >> H;
  for (int i = 0; i < (N); ++i) {
    cin >> a >> b[i];
    chmax(maxv, a);
  }
  sort(b, b + N, greater<int>());
  int cnt = 0;
  for (int i = 0; i < N && b[i] > maxv; ++i) {
    ++cnt;
    H -= b[i];
  }
  if (H > 0) {
    cnt += (H + maxv - 1) / maxv;
  }
  cout << (cnt) << '\n';
}
