#include <bits/stdc++.h>
using namespace std;
bool comp(int a, int b) { return a > b; }
int main() {
  int n = 0, h = 0, ai = 0, bi = 0, i = 0, j = 0, mxk = 0, cnt = 0;
  int warr[100010] = {};
  int tarr[100010] = {};
  scanf("%d%d", &n, &h);
  for (i = 0; i < n; ++i) {
    scanf("%d%d", warr + i, tarr + i);
    mxk = max(mxk, warr[i]);
  }
  sort(tarr, tarr + n, comp);
  i = 0;
  while (h > 0 && i != n) {
    h -= tarr[i];
    ++i;
    ++cnt;
  }
  if (h > 0) cnt += ceil(h / (double)mxk);
  printf("%d\n", cnt);
  return 0;
}
