#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,et[2*DD],dep[2*DD],k,id[DD];
int rmq[18][2*DD];
vi v[DD];
void dfs(int x,int depth) {
    et[++k]=x;
    id[x]=k;
    dep[k]=depth;
    for (auto e:v[x]) {
        dfs(e,depth+1);
        et[++k]=x;
        dep[k]=depth;
    }
}
int main(){
    f>>n>>m;
    for (int i=2; i<=n; ++i) {
        int x;
        f>>x;
        v[x].pb(i);
    }
    dfs(1,0);
    for (int i=1; i<=k; ++i)
        rmq[0][i]=i;
    for (int i=1; i<=17; ++i) {
        for (int j=1; j+(1<<i)-1<=k; ++j) {
            int x=rmq[i-1][j];
            int y=rmq[i-1][j+(1<<(i-1))];
            rmq[i][j]=dep[x]<dep[y]?x:y;
        }
    }
    while (m--) {
        int x,y;
        f>>x>>y;
        int xx=min(id[x],id[y]);
        int yy=max(id[x],id[y]);
        int lg=__lg(yy-xx+1);
        int a=rmq[lg][xx];
        int b=rmq[lg][yy-(1<<lg)+1];
        int mn=dep[a]<dep[b]?a:b;
        g<<et[mn]<<nl;
    }
    system("pause");
    return 0;
}