#include <bits/stdc++.h>
using namespace std;
const long long MOD_CONST = 1000000007;
const long long BIG_NUM = 1000000000000000000;
int main() {
  int n, h;
  cin >> n >> h;
  priority_queue<pair<int, int>> throwSword;
  int maxA_i = 0;
  int maxA = 0;
  int maxA_B = 0;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    throwSword.push(make_pair(b, i));
    if (maxA < a) {
      maxA = a;
      maxA_i = i;
    }
    if (maxA == a && maxA_B > b) {
      maxA_i = i;
      maxA_B = b;
    }
  }
  int cnt = 0;
  int maxB = 0;
  while (!throwSword.empty()) {
    pair<int, int> ts = throwSword.top();
    throwSword.pop();
    if (ts.second = maxA_i) {
      maxB = max(maxB, ts.first);
      continue;
    }
    if (ts.first <= maxA) {
      maxB = max(maxB, ts.first);
      break;
    } else {
      h -= ts.first;
      cnt++;
    }
    if (h <= 0) {
      break;
    }
  }
  if (h > 0 && maxA < maxB) {
    h -= maxB;
    cnt++;
  }
  if (h > 0) {
    cnt += (h / maxA);
    if (h % maxA != 0) {
      cnt++;
    }
  }
  cout << cnt << endl;
}
