#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, h;
  int p = -1;
  int max = 0;
  int b[100001];
  long long int count = 0;
  cin >> n >> h;
  for (int i = (1); i <= (n); i++) {
    int a;
    cin >> a >> b[i];
    if (max < a) {
      max = a;
    }
  }
  sort(b, b + n);
  for (int i = (1); i <= (n); i++) {
    if (b[i] > max) {
      p = i;
      break;
    }
  }
  if (p == -1) {
    if (h % max == 0) {
      count = h / max;
    } else {
      count = h / max;
      count++;
    }
  } else {
    for (int i = (n); i >= (p); i--) {
      h -= b[i];
      count++;
      if (h <= 0) {
        break;
      }
    }
    if (h > 0) {
      if (h % max == 0) {
        count += h / max;
      } else {
        count += h / max;
        count++;
      }
    }
  }
  cout << count << endl;
  return 0;
}
