#include <bits/stdc++.h>
using namespace std;
long long A_MAX = -1;
long long B[10000];
int N;
long long H;
int main() {
  cin >> N;
  cin >> H;
  long long a, b;
  for (int i = 0; i < N; i++) {
    cin >> a >> b;
    A_MAX = max(A_MAX, a);
    B[i] = b;
  }
  sort(B, B + N);
  int result = 0;
  int cou = N - 1;
  while (A_MAX < B[cou] && 0 <= cou) {
    H -= B[cou];
    cou--;
    result++;
    if (H <= 0) {
      cout << result << endl;
      return 0;
    }
  }
  int temp = H / A_MAX;
  if (H % A_MAX != 0) temp++;
  result += temp;
  cout << result << endl;
  return 0;
}
