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

const int MAX_N = 1e5 + 5;
int A[MAX_N], B[MAX_N];

int main(){
    int n, h; cin >> n >> h;
    for(int i=0;i<n;i++) cin >> A[i] >> B[i];

    sort(A, A+n); sort(B, B+n);
    reverse(A, A+n); reverse(B, B+n);

    int ans = 0;
    for(int i=0;i<n && 0<h;i++){
        if(B[i]<A[0]) break;
        h -= B[i]; ans++;
    }

    if(0<h) ans += (h+A[0]-1) / A[0];
    cout << ans << endl;
    return 0;   
}
