#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<ll,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 1000006
#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,q;
vi v[DD];
int up[DD][19],dep[DD],sz[DD];
void dfs(int x,int p){
    up[x][0]=p;
    dep[x]=dep[p]+1;
    sz[x]=1;
    for(int i=1; i<19; ++i)
        up[x][i]=up[up[x][i-1]][i-1];
    for(auto e:v[x]){
        dfs(e,x);
        sz[x]+=sz[e];
    }
}
int lca(int x, int y){
    if(dep[x]<dep[y]) swap(x,y);
    for(int k=18; k>=0; --k){
        if(dep[up[x][k]]>=dep[y]) x=up[x][k];
    }
    if(x==y) return x;
    for(int k=18; k>=0; --k){
        if(up[x][k]!=up[y][k]){
            x=up[x][k];
            y=up[y][k];
        }
    }
    return up[x][0];
}
int main(){
    f>>n>>q;
    for(int i=1; i<n; ++i){
        int x;
        f>>x;
        v[x].pb(i+1);
    }
    dfs(1,0);
    while(q--){
        int x,y;
        f>>x>>y;
        g<<lca(x,y)<<nl;
    }
    return 0;
}