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

const int N = 100010;
vector<int> v[N];
int dao[N];
bool vis[N];
int n;
double z, r, sum;

void dfs(int x, double z)
{
    vis[x] = true;
    if (dao[x])
        sum += dao[x] * z;
    for (auto c : v[x])
    {
        if (!vis[c]) dfs(c, z * r);
    }
}

int main()
{

    cin >> n >> z >> r;
    r = (100 - r) / 100;
    for (int i = 0; i < n; i++)
    {
        int k;
        cin >> k;
        if (!k) cin >> dao[i];
        while (k--)
        {
            int x; cin >> x;
            v[i].push_back(x);
        }
    }
    dfs(0, z);
    cout << (int)sum << endl;
    return 0;
}