LCA

#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <deque>
#include <list>
#include <iterator>
#include <functional>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include <cmath>
#include <climits>
#include <ctime>
#include <cassert>

using namespace std;


typedef long long ll;
typedef long  double ld;
typedef pair<double, double> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pld;
typedef pair<short, short> pss;
#define fi first
#define se second
#define mp make_pair
#define pb push_back



/////// begin
const int MAXN = 200 * 1000;
vector <int> g[MAXN];
int tin[MAXN], tout[MAXN], pr[20][MAXN];
bool was[MAXN];
int t = 0;

void dfs(int v, int _pr){
    if (was[v]) return;
    was[v] = 1;
    tin[v] = t++;
    pr[0][v] = _pr;
    for (int u: g[v])
        dfs(u, v);
    tout[v] = t++;
}

bool is_pr(int v, int u){
    return (tin[v] >= tin[u] && tout[v] <= tout[u]);
}

int get_lca(int u, int v){
    if (is_pr(u, v)) return v;
    for (int i = 19; i >= 0; i--){
        if (!is_pr(u, pr[i][v]))
            v = pr[i][v];
    }
    return pr[0][v];
}

int main() {
#ifdef HOME
    assert(freopen("input.txt", "r", stdin));
    assert(freopen("output.txt", "w", stdout));
#else
  //freopen(FILE ".in", "r", stdin);
  //freopen(FILE ".out", "w", stdout);
#endif
    //ios_base::sync_with_stdio(false);
    //cin.tie(0);
    int n, m;
    cin >> n >> m;
    for (int i = 1; i < n; i ++){
        int a;
        cin >> a;
        g[a].pb(i);
        g[i].pb(a);
    }
    memset(was, 0, sizeof was);
    dfs(0, 0);
    for (int i = 1; i < 20; i++)
        for (int j = 0; j < n; j++){
            pr[i][j] = pr[i - 1][pr[i - 1][j]];
        }



    int a1, a2;
    ll x, y, z;
    int la = 0;
    ll ans = 0;
    cin >> a1 >> a2 >> x >> y >> z;
    for (int i = 0; i < m; i++){
        //cout << (a1 + la) % n << " " << a2 << endl;
        la = get_lca((a1 + la) % n, a2) ;
        ans += la;
        a1 = (int)((a1 * x + a2 * y + z) % n);
        a2 = (int)((a2 * x + a1 * y + z) % n);
    }
    cout << ans << endl;

    return 0;
}

// end