#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  scanf("%d%d", &N, &H);
  static int B[100002];
  int amax = 0;
  int count = 0;
  int D = 0;
  for (int i = 0; i < (N); ++i) {
    int a, b;
    scanf("%d%d", &a, &b);
    amax = max(a, amax);
    B[i] = b;
  }
  sort(B, B + N, greater<int>());
  int ind = 0;
  while (ind < N) {
    if (B[ind] >= amax) {
      count++;
      D = D + B[ind];
    } else {
      break;
    }
    ind++;
  }
  if (H <= D) {
    printf("%d\n", count);
    return 0;
  }
  if (((H - D) % amax) == 0) {
    count += (H - D) / amax;
  } else {
    count += ((H - D) / amax) + 1;
  }
  printf("%d\n", count);
  return 0;
}
