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

#define ll long long

bool cmp(ll a, ll b)

{
    return a > b;
}

int main()

{
    ll n, h;
    cin >> n >> h;
    ll thrown[n + 5];

    ll mx = INT_MIN;
    for(int i = 0; i < n; i++) {
        ll tmp;
        cin >> tmp >> thrown[i];
        mx = max(tmp, mx);
    }

    sort(thrown, thrown + n, cmp);

    ll cnt = 0, sum = 0;
    for(int i = 0; i < n; i++) {
        if(thrown[i] < mx)
            break;
        sum += thrown[i];
        cnt++;
        if(sum >= h)
            break;
    }

    if(sum < h) {
        cnt = cnt + ( (h - sum) / mx);
        if((h - sum) % mx != 0)
            cnt++;
    }

    cout << cnt << endl;

    return 0;
}

