#include <bits/stdc++.h>
int main(void) {
  int N, H;
  int chk = -1;
  int max = 0;
  int sum = 0;
  scanf("%d %d", &N, &H);
  int a[N], b[N];
  for (int i = 0; i < N; i++) {
    scanf("%d %d", &a[i], &b[i]);
  }
  while (1) {
    chk = -1;
    max = 0;
    for (int i = 0; i < N; i++) {
      if (max < a[i]) {
        max = a[i];
        chk = 0;
      }
      if (max < b[i]) {
        max = b[i];
        chk = 1;
      }
    }
    if (chk == 1) {
      for (int i = 0; i < N; i++) {
        if (max == b[i]) {
          b[i] = 0;
          H = H - max;
          sum++;
          if (H <= 0) {
            printf("%d", sum);
            return 0;
          }
        }
      }
    } else if (chk == 0) {
      while (1) {
        H = H - max;
        sum++;
        if (H <= 0) {
          printf("%d", sum);
          return 0;
        }
      }
    }
  }
  return 0;
}
