#include <bits/stdc++.h>
using namespace std;
#define rep0(i,n) for(ll (i) = 0; (i) < (n); ++(i))
#define rrep0(i,n) for(ll (i) = (n) - 1; (i) >= 0; --(i))
#define rep1(i,n) for(ll (i) = 1; (i) <= (n); ++(i))
#define rrep1(i,n) for(ll (i) = (n); (i) >= 1; --(i))
#define nfor(i,a,b) for(ll (i) = (a); (i) < (b); ++(i))
#define rnfor(i,a,b) for(ll (i) = (a) - 1; (i) >= (b); --(i))
#define ll long long
#define mod (1000000007)
#define pf(x) cout << (x) << endl
#define all(x) (x).begin(),(x).end()
const ll inf = 1e9;

ll gcd(ll a,ll b){
    if(a < b)swap(a, b);
    if(b == 0) return a;
    return gcd(b,a%b);
}

ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b;
}

ll factorial(ll n){
    ll t = 1;
    rep1(i, n)t *= i;
    return t;
}

ll combinations(ll n, ll k) {
    ll r = 1;
    rep1(i, k)r = r * n-- / i;
    return r;
}

int main(){
    ll n,h,ans = 0;
    cin >> n >> h;
    vector<ll> a(n),b(n);
    rep0(i, n)cin >> a[i] >> b[i];
    sort(all(a),greater<>());
    sort(all(b),greater<>());
    rep0(i, n){
        if(b[i] <= a[0] || h <= 0)break;
        ++ans;
        h -= b[i];
    }
    if(a[0] > 0)ans += (h + a[0] - 1) / a[0];
    pf(ans);
    return 0;
}
