LCA

/*
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡀⠤⠲⠦⠉⠉⠉⠏⠉⠒⢄⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡠⠲⠃⢀⣤⠀⠀⠀⠲⠂⠀⠠⠆⠀⠙⢄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢀⡔⠁⣤⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⡆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⢀⠊⠁⠀⢁⡴⠚⠉⣉⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣀⠠⠤⠔⠒⡄⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⡆⢰⠆⠀⠋⣠⠔⠉⠁⣀⡠⠄⠒⠂⠀⠀⠀⠀⠀⠀⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠔⠊⠁⠀⠀⠀⠀⠀⣠⡴⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⢠⡆⠀⠀⠀⡜⠁⣠⠔⠋⢁⡔⠒⠒⠤⡀⠀⠀⠀⠀⡐⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠎⠀⠀⠀⢀⣀⣤⣶⡾⠋⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⡆⡶⠀⠀⢀⡜⠁⢀⣀⢸⠀⠀⠀⠀⠈⢆⠀⠀⡜⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠤⠊⠁⠀⢀⡀⣴⡿⠿⠛⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠰⡀⠀⠀⠘⠀⡞⠁⠀⠉⢇⠀⣿⣄⠀⠈⡆⠀⠕⠒⠉⣉⡒⡄⠀⠀⠀⠀⢀⠤⠊⠁⢀⡠⠔⠊⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠑⢄⡀⠀⠀⢇⠀⣤⡄⠈⢢⡈⠻⡖⢀⡞⣀⠔⠊⠁⠀⠀⠉⠐⠒⠠⢎⢁⡠⠔⠂⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠉⠉⠉⢂⠘⢿⣦⡇⠉⠓⢶⡫⠞⠁⣀⣤⣤⣤⣤⣤⣤⣤⠴⠛⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢡⠦⠭⡇⠀⡠⠊⠀⣠⣮⣬⣿⣿⣿⣿⣿⣯⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢰⠁⢀⠔⡧⠊⠀⢀⡜⠁⠙⣿⣿⣿⡿⠟⠋⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠸⣀⣡⠎⠀⠀⢠⠊⠀⠀⠀⣸⣿⣿⣷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠃⠀⠀⣰⣧⣀⣀⡠⣴⣿⣿⣿⣿⣿⣆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢧⣤⣤⣾⡿⠿⠋⠁⠀⢹⣿⣿⣿⣿⣿⣿⡆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠁⠀⠀⠀⠀⠀⠀⢸⣿⣿⣿⣿⣿⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣼⣿⣿⣿⣿⣿⣿⣿⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⣿⠿⠛⠛⠛⠛⠻⢿⠇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡸⠀⠀⠀⠀⠀⠀⠀⡸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢰⠁⡰⢤⣀⣀⡄⢠⠞⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
*/

#include <iostream>
#include <string>
#include <sstream>
#include <cmath>
#include <memory.h>
#include <algorithm>
#include <stack>
#include <deque>
#include <iomanip>
#include <stdio.h>
#include <queue>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <ctime>
#include <cstdlib>
#define int long long
#define pii pair <int, int>
#define pb push_back
#define all(vc) vc.begin(), vc.end()
#define fir first
#define sec second
#define endl "\n"
#define un unsigned
#define INF 1000000009
#define double long double
using namespace std;

const int N = 100009, R = 1 << 20, MOD = 1e9 + 7, ABC = 26;

int logn = 0;
int cur = 0;

void dfs(vector<vector<int>> &jump, vector<vector<int>> &gr, vector<int>& up_time, vector<int>& time_in, int v, int p)
{
    time_in[v] = cur;
    cur++;

    jump[v][0] = p;

    for (int i = 1; i < logn; i++)
    {
        jump[v][i] = jump[jump[v][i - 1]][i - 1];
    }

    for (auto u : gr[v])
    {
        if (u != p)
        {
            dfs(jump, gr, up_time, time_in, u, v);
        }
    }

    up_time[v] = cur;
    cur++;
    return;
}

bool check(vector<int>& time_in, vector<int>& up_time, int a, int b)
{
    if (time_in[a] <= time_in[b] && up_time[b] <= up_time[a])
    {
        return true;
    }
    else
    {
        return false;
    }
}

int lca(vector<vector<int>>& jump, vector<int>& time_in, vector<int>& up_time, int a, int b)
{
    if (check(time_in, up_time, a, b))
    {
        return a;
    }

    if (check(time_in, up_time, b, a))
    {
        return b;
    }

    for (int i = logn - 1; i >= 0; i--)
    {
        if (!check(time_in, up_time, jump[a][i], b))
        {
            a = jump[a][i];
        }
    }

    return jump[a][0];
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    srand(time(0));

    int n, m;
    cin >> n >> m;

    vector<int> pr(n);
    vector<vector<int>> vc(n);

    for (int i = 1; i < n; i++)
    {
        cin >> pr[i];
        vc[pr[i]].push_back(i);
    }

    while ((1 << logn) <= n)
    {
        logn++;
    }

    vector<int> up_time(n), time_in(n);
    vector<vector<int>> jump(n, vector<int>(logn));

    dfs(jump, vc, up_time, time_in, 0, 0);

    vector<int> a(2 * m + 1);

    cin >> a[1] >> a[2];

    int x, y, z;
    cin >> x >> y >> z;

    int anss = 0;

    for (int i = 3; i <= 2 * m; i++)
    {
        a[i] = (x * a[i - 2] + y * a[i - 1] + z) % n;
    }

    int aa = a[1], b = a[2];

    for (int i = 2; i <= m + 1; i++)
    {
        int ans = lca(jump, time_in, up_time, aa, b);

        //cout << aa << " " << b << " " << ans << endl;

        anss += ans;

        if (i != m + 1)
        {
            aa = (a[2 * i - 1] + ans) % n;
            b = a[2 * i];
        }
    }

    cout << anss;
    return 0;
}