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蒟蒻只AC两个点，求助

#include<bits/stdc++.h>
using namespace std;
#define N 8000100

inline int read(){
	int x = 0, s = 1;
	char c = getchar();
	while(!isdigit(c)){
		if(c == '-') s = -1;
		c = getchar();
	}
	while(isdigit(c)){
		x = (x << 1) + (x << 3) + (c ^ '0');
		c = getchar();
	}
	return x * s;
}

namespace get_data{
	#define ui unsigned int
	ui s;
	inline void get_s(){
		cin >> s;
		return ;
	}
	inline ui get(ui x) {
		x ^= x << 13;
		x ^= x >> 17;
		x ^= x << 5;
		return s = x; 
	}

}

struct node{
	int u, v;
	int next;
} t[N << 2];
int f[N];
int fa[N], son[N];
int rev[N], dfn[N], id = 0;
int sz[N], top[N], deth[N];
int ltans[N];

int bian = 0;
inline void add(int u, int v){
	t[++bian] = (node){u, v, f[u]}, f[u] = bian;
	t[++bian] = (node){v, u, f[v]}, f[v] = bian;
	return ;
}


void dfs1(int now){
	sz[now] = 1;
	deth[now] = deth[fa[now]] + 1;
	int maxn = -1;
	for(int i = f[now]; i;i = t[i].next){
		int v = t[i].v, u = t[i].u;
		if(v != fa[u]){
			dfs1(v);
			sz[u] += sz[v];
			if(sz[v] > maxn){
				son[u] = v;
				maxn = sz[v];
			}
		}
	}
	return ;
}

void dfs2(int now, int rt){
	top[now] = rt, dfn[now] = ++id, rev[id] = now;
	if(!son[now]) return ;
	dfs2(son[now], rt);
	for(int i = f[now]; i;i = t[i].next){
		int v = t[i].v, u = t[i].u;
		if(v != fa[u] && v != son[u]){
			dfs2(v, v);
		}
	}
	return ;
}

int jump(int x, int k){
	int d = deth[x] - k;
	while(deth[top[x]] > d) x = fa[top[x]];
	d = deth[x] - d;
	return rev[dfn[x] - d];
}

int main(){
	int n = read(), q = read();   get_data::get_s();
	int root;
	for(int i = 1;i <= n; i++){
		fa[i] = read();
		add(fa[i], i);
		if(fa[i] == 0) root = i;
	}
	deth[root] = 1;
	dfs1(root);
	dfs2(root, root);
	int ans = 0;
	for(int i = 1;i <= q; i++){
		int x = ((get_data::get(get_data::s) ^ ltans[i-1] ) % n) + 1;
		int k = (get_data::get(get_data::s) ^ ltans[i-1] ) % deth[x];
		ltans[i] = jump(x, k);
		ans ^= (i * ltans[i]);
	}
	printf("%d\n", ans);
	return 0;
}