#include <iostream>
#include <string>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <numeric>
#include <regex>

#define FOR(i, f, n) for(int (i) = (f); (i) < (n); (i)++)
#define RFOR(i, f, n) for(int (i) = (f); (i) >= (n); (i)--)
#define REP(i, n) for(int (i) = 0; (i) < (n); (i)++)
#define RREP(i, n) for(int (i) = (n); (i) >= 0; (i)--)
#define rep(i, n) for(int (i) = 0; (i) < (n); (i)++)
#define rrep(i, n) for(int (i) = (n); (i) >= 0; (i)--)
#define forin(i, a) for(auto i: (a))
#define p(...) printf(__VA_ARGS__); cout << endl;
#define in(...) __VA_ARGS__; input__(__VA_ARGS__);
#define input(...) in(__VA_ARGS__)
#define out(...) output__(__VA_ARGS__);
#define output(...) out(__VA_ARGS__)
#define list_input(x, n) x[(n)]; for(int (i) = 0; (i) < (n); (i)++) cin >> x[i];
#define lambda(a, b, c) [](auto const &a, auto const &b){ return c ;}
#define key(t, x, compare) [](const t &a, const t &b){ return a x compare b x ;}
#define unless(a) if(!(a))

using namespace std;

using pii = pair<int, int>;

template <class... T>
void input__(T &...a) {
  for(auto v: {&a...}) {
    cin >> *v;
  }
}

void output__(){
  cout << endl;
}

template <class Head, class... T>
void output__(Head const &v, T const &...a) {
  if(sizeof...(a) == 0) {
    cout << v;
  } else {
    cout << v << " ";
  }
  output__(a...);
}

int main(){
  int in(n, h);
  int a[n], b[n];
  rep(i, n) {
    cin >> a[i] >> b[i];
  }

  int max_value = *max_element(a, a + n);
  int cnt = 0;
  sort(b, b + n, lambda(left, right, left > right));
  rep(i, n) {
    if(max_value >= b[i]) {
      break;
    }

    h -= b[i];
    cnt++;
  }

  out((h + max_value - 1) / max_value + cnt);
}
