#include <bits/stdc++.h>
int main() {
  int s[200000][5];
  int n, i, j;
  int HP;
  int max;
  int katana;
  int exdamage = 0;
  int exkatana = 0;
  int result = 0;
  scanf("%d", &n);
  scanf("%d", &HP);
  for (i = 0; i < n; i++) {
    for (j = 0; j <= 1; j++) {
      scanf("%d", &s[i][j]);
    }
  }
  for (i = 0; i < n; i++) {
    if (s[i][0] > max) {
      max = s[i][0];
    }
  }
  for (i = 0; i < n; i++) {
    if (s[i][1] > max) {
      exdamage = exdamage + s[i][1];
      exkatana++;
    }
  }
  for (i = 0; i < 1000010000; i++) {
    if (exdamage >= HP) {
      result = result + exkatana;
      printf("%d", result);
      break;
    }
    HP = HP - max;
    result++;
  }
}
