#include <bits/stdc++.h>
using namespace std;
int arr_wieid[100001], arr_throw[100001];
bool mycompare(const int& a, const int& b) { return a > b; }
int main() {
  int N, H, i, count = 0, ans = 0, pos_t = 0;
  scanf("%d %d", &N, &H);
  for (i = 0; i < N; i++) {
    scanf("%d %d", &arr_wieid[i], arr_throw[i]);
  }
  sort(arr_wieid, arr_wieid + N, mycompare);
  sort(arr_throw, arr_throw + N, mycompare);
  while (H > 0) {
    if (arr_throw[pos_t] > arr_wieid[0]) {
      H -= arr_throw[pos_t++];
      ans++;
    } else {
      ans = H / arr_wieid[0];
      ans = H % arr_wieid[0] == 0 ? 0 : 1;
      break;
    }
  }
  printf("%d", ans);
  return 0;
}
