#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int n, h;
    cin >> n >> h;
    int a[n], b[n];
    int mx = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i] >> b[i];
        mx = max(mx, a[i]);
    }
    sort(b, b+n);
    reverse(b, b+n);
    int i;
    for (i = 0; i < n && b[i] > mx && h > 0; i++) {
        h -= b[i];
    }
    h = max(0, h);
    cout << i + (h+mx-1) / mx;
    return 0;
}