#include <vector>
#include<iostream>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <fstream>
#include <string>
#include <set>
#include <deque>
#include <queue>
#include <map>
#include <bitset>
#include <random>
#include <cassert>
#include <unordered_map>
#include <unordered_set>
#include<math.h>
using namespace std;
typedef unsigned int ui;
typedef long long             ll;
typedef unsigned long long     ull;
typedef long double            ld;
#define endl              "\n"
#define all(a)            a.begin(), a.end()
#define allr(a)           a.rbegin(), a.rend()
#define pb                push_back
#define pikachu           push_back
#define F                 first
#define S                 second
ll inf = 1e18;
ld eps = 1e-18;
const ll maxn = 2e5 + 10;
const ll LG = 20;
ll lg[maxn];
ll h[maxn], tout[maxn], tin[maxn];
ll n, m;
vector<ll> g[maxn];
ll t = 0;
vector<ll> tr;
ll sp[LG][2 * maxn][2];
void dfs(ll a, ll ls) {
    if (tin[a] == -1) {
        tin[a] = t;
    }
    tr.pb(a);
    t++;
    if (ls != -1)
        h[a] = h[ls] + 1;
    for (ll &x : g[a]) {
        if (x != ls) {
            dfs(x, a);
            tr.pb(a);
            t++;
        }
    }
    tout[a] = t;
}

ll lca(ll a, ll b) {
    if (tin[a] > tin[b])
        swap(a, b);
    ll d = (tin[b] - tin[a] + 1);
    ll kek = lg[d];
    if (sp[kek][tin[a]][0] < sp[kek][tin[b] - (1 << kek) + 1][0]) {
        return sp[kek][tin[a]][1];
    }
    return sp[kek][tin[b] - (1 << kek) + 1][1];
}

void solve() {
    for (ll i = 0; i < maxn; i++) {
        tin[i] = -1;
    }
    for (ll i = 2; i < maxn;i++) {
        lg[i] = lg[i / 2] + 1;
    }
    cin >> n >> m;
    for (ll i = 1; i < n;i++) {
        ll a;
        cin >> a;
        g[i].pb(a);
        g[a].pb(i);
    }
    dfs(0, -1);
    ll sz = t;
    for (ll i = 0; i < sz;i++) {
        sp[0][i][0] = h[tr[i]];
        sp[0][i][1] = tr[i];
    }
    for (ll i = sz; i < 2 * maxn;i++) sp[0][i][0] = 1e9;
    for (ll i = 1; i < LG;i++) {
        for (ll j = 0; j + (1 << i) <= sz; j++) {
            if (sp[i - 1][j][0] < sp[i - 1][j + (1 << (i - 1))][0]) {
                sp[i][j][0] = sp[i - 1][j][0];
                sp[i][j][1] = sp[i - 1][j][1];
            }
            else {
                sp[i][j][0] = sp[i - 1][j + (1 << (i - 1))][0];
                sp[i][j][1] = sp[i - 1][j + (1 << (i - 1))][1];
            }
        }
    }
    ll a, b;
    cin >> a >> b;
    ll x, y, z;
    ll ans = 0;
    cin >> x >> y >> z;
    ll sum = 0;
    while (m--) {
        ll a1 = (a + ans) % n;
        ll a2 = b;
        ans = lca(a1, a2);
        sum += ans;
        a = (x * a + b * y + z) % n;
        b = (x * b + a * y + z) % n;
    }
    cout << sum << endl;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t = 1;
    //cin >> t;
    //cout << fixed << setprecision(18);
    while (t--) {
        solve();
    }
}