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

int main() {
    int N;
    double Z, r;
    cin >> N >> Z >> r;

    vector<vector<int>> tree(N);        // 存储师傅到徒弟的关系
    vector<bool> isLeaf(N, false);      // 标记是否是得道者（即叶子节点）
    vector<double> multiplier(N, 1.0);   // 得道者的功力倍数
    vector<int> depth(N, 0);            // 每个节点的深度（代数）

    for (int i = 0; i < N; ++i) {
        int K;
        cin >> K;
        if (K == 0) {
            isLeaf[i] = true;
            double m;
            cin >> m;
            multiplier[i] = m;
        } else {
            for (int j = 0; j < K; ++j) {
                int child;
                cin >> child;
                tree[i].push_back(child);
            }
        }
    }

    // BFS 遍历整棵树并记录深度
    queue<int> q;
    q.push(0);  // 祖师爷编号为0
    depth[0] = 0;

    while (!q.empty()) {
        int current = q.front();
        q.pop();
        for (int child : tree[current]) {
            depth[child] = depth[current] + 1;
            q.push(child);
        }
    }

    // 计算所有得道者的功力
    double totalPower = 0.0;
    double rate = 1.0 - r / 100.0;

    for (int i = 0; i < N; ++i) {
        if (isLeaf[i]) {
            double power = Z * pow(rate, depth[i]) * multiplier[i];
            totalPower += power;
        }
    }

    // 输出功力总值的整数部分
    cout << (long long)(totalPower) << endl;

    return 0;
}