#include <bits/stdc++.h>
#define int long long
#define Task "ADVERT"
#define watch(x) cout << #x << " = " << x << endl
#define F first
#define S second
#define pb push_back
#define mp make_pair

using namespace std;

typedef pair <int,int> pii;
typedef pair <pii,int> ppi;
typedef pair <int,pii> pip;
typedef pair <pii,pii> ppp;

const int oo = 1e12;
const int MOD = 0x3f3f3f3f;
const int MAXN = 1e5 + 1;

int n, w, h, a[MAXN], b[MAXN];

bool advert(double k)
{
    double H = h, W = w;
    int i = 1;
    while (H >= 0 && i <= n)
    {
        double ai = a[i] * k, bi = b[i] * k;
        if (b[i] != b[i - 1])
        {
            W = w - ai;
            H -= bi;
            if (W < 0) return 0;
        }
        else
        {
            if (W >= ai)
            {
                W -= ai;
            }
            else
            {
                W = w - ai;
                H -= bi;
                if (W < 0) return 0;
            }
        }
        ++i;
    }
    if (H < 0) return false;
    return true;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    cin >> n >> w >> h;
    for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
    double l = 0, r = 1e9;
    while (r - l > 1e-4)
    {
        double mid = (l + r) / 2;
        if (advert(mid)) l = mid;
        else r = mid;
    }
    cout << setprecision(6) << fixed << l;
    return 0;
}