#include <bits/stdc++.h>
using namespace std;
#define REP(i, n) for(int i = 0; i < n; i++)
#define ALL(a) (a).begin(),(a).end()

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int n, HP;
    cin >> n >> HP;
    vector<int> a(n), b(n);
    REP(i, n) cin >> a[i] >> b[i];

    sort(ALL(b), greater<int>());
    int amax = *std::max_element(ALL(a));
    int ans = 0;
    REP(i, n) {
        if (HP <= 0 || b[i] < amax) break;
        HP -= b[i];
        ans++;
    }

    if (HP > 0) ans += (HP + amax - 1) / amax;
    cout << ans << endl;
    return 0;
}