#include <bits/stdc++.h>
int main(void) {
  int n, h;
  int a[100000], b[100000];
  scanf("%d%d", &n, &h);
  int i, j, amax = 0;
  for (i = 0; i < n; i++) {
    scanf("%d%d", &a[i], &b[i]);
    if (amax < a[i]) amax = a[i];
  }
  int tmp, index, max;
  for (i = 0; i < n - 1; i++) {
    max = 0;
    index = i;
    for (j = i; j < n; j++) {
      if (max < b[j]) {
        max = b[j];
        index = j;
      }
    }
    tmp = b[i];
    b[i] = max;
    b[index] = tmp;
  }
  int count = 0;
  for (i = 0; i < n; i++) {
    if (b[i] >= amax)
      h -= b[i];
    else
      break;
    count++;
    if (h <= 0) {
      printf("%d", count);
      return 0;
    }
  }
  while (1) {
    count++;
    h -= amax;
    if (h <= 0) {
      printf("%d", count);
      return 0;
    }
  }
  return 0;
}
