#include <bits/stdc++.h>
int main(void) {
  int n, i, j, k, h, ans = 0, t;
  scanf("%d %d", &n, &h);
  int a[n], b[n], sum[n], num;
  for (i = 0; i < n; ++i) scanf("%d %d", &a[i], &b[i]);
  for (i = 0; i < n; ++i)
    for (j = i + 1; j < n; ++j) {
      if (a[i] < a[j]) t = a[i], a[i] = a[j], a[j] = t;
      if (b[i] < b[j]) t = b[i], b[i] = b[j], b[j] = t;
    }
  sum[0] = b[0];
  if (sum[0] >= h) {
    printf("1\n");
    return 0;
  }
  for (i = 0; i < n; ++i) {
    sum[i] = b[i] + sum[i - 1];
    if (sum[i] >= h) {
      printf("%d\n", i + 1);
      return 0;
    }
  }
  for (i = 0; i < n; ++i) {
    if (a[0] > b[i]) {
      num = i;
      break;
    }
  }
  ans += num;
  h -= sum[num - 1];
  ans += (h + a[0] - 1) / a[0];
  printf("%d\n", ans);
  return 0;
}
