#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops,inline")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define setinf(x) memset(x,0x3f3f3f3f,sizeof(x));
#define set0(x) memset(x,0,sizeof(x));
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define INF 0x3f3f3f3f
#define vi vector<int>
#define ll long long
#define vll vector<ll>
#define pb push_back
#define fi first
#define se second
#define DD 100001
#define nl '\n'
using namespace std;
const string file="lca";
ifstream f(file+".in");
ofstream g(file+".out");
//#define f cin
//#define g cout
int n,m;
vi v[DD];

struct LCA {
    int n,k=0;
    const int LG=18;
    vector<int>et,dep,id;
    vector<vector<int>>rmq;

    LCA(int _n, vector<int> v[]) {
        n=_n;
        et.resize(2*(n+1));
        dep.resize(2*(n+1));
        id.resize(n+1);
        rmq.resize(LG,vector<int>(2*(n+1)));
        dfs(1,0);
        build();
    }
    void dfs(int x, int depth) {
        et[++k]=x;
        dep[k]=depth;
        id[x]=k;
        for (auto e:v[x]) {
            dfs(e,depth+1);
            et[++k]=x;
            dep[k]=depth;
        }
    }
    void build() {
        for (int i=1; i<=k; ++i) rmq[0][i]=i;
        for (int i=1; i<LG; ++i) {
            for (int j=1; j+(1<<i)-1<=k; ++j) {
                int a=rmq[i-1][j];
                int b=rmq[i-1][j+(1<<(i-1))];
                rmq[i][j]=dep[a]<dep[b]?a:b;
            }
        }
    }
    int lca(int x, int y) {
        int l=min(id[x],id[y]);
        int r=max(id[x],id[y]);
        int lg=__lg(r-l+1);
        int a=rmq[lg][l];
        int b=rmq[lg][r-(1<<lg)+1];
        return dep[a]<dep[b]?et[a]:et[b];
    }
};

int main(){
    f>>n>>m;
    for (int i=2; i<=n; ++i) {
        int x;
        f>>x;
        v[x].pb(i);
    }
    LCA lca(n,v);
    while (m--) {
        int x,y;
        f>>x>>y;
        g<<lca.lca(x,y)<<nl;
    }
    system("pause");
    return 0;
}