#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
const int NMAX=100005;
int str[NMAX][21];
vector<int> parent,level,sol;
vector<vector<int>> graph;
void bfs(int start)
{
    queue<int> q; q.push(start); level[start]=0;
    while(!q.empty())
    {
        int node=q.front(); q.pop();
        for(int neighbor:graph[node])
            if(level[neighbor]==-1)
        {
            level[neighbor]=level[node]+1;
            q.push(neighbor);
        }
    }
}
int main()
{
    int n,m; cin>>n>>m;
    parent.resize(n+1); level.resize(n+1,-1);
    graph.resize(n+1,vector<int>());
    for(int i=1;i<=n-1;i++) {cin>>parent[i+1];
    graph[i+1].push_back(parent[i+1]);
    graph[parent[i+1]].push_back(i+1);
    }
    parent[1]=1;
    for(int i=1;i<=n;i++) str[i][0]=parent[i];
    for(int j=1;j<=20;j++)
    for(int i=1;i<=n;i++){
        str[i][j]=str[str[i][j-1]][j-1];
    }
    bfs(1);
    for(int i=1;i<=m;i++)
    {
        int x,y; cin>>x>>y;
        if(level[x]>level[y])
        {
            int dif=level[x]-level[y];
            for(int j=20;j>=0;j--)
            if((1<<j)<=dif)
            {
                x=str[x][j];
                dif-=1<<j;
            }
        }
        else if(level[y]>level[x])
        {
            int dif=level[y]-level[x];
            for(int j=20;j>=0;j--)
            if((1<<j)<=dif)
            {
                y=str[y][j];
                dif-=1<<j;
            }
        }if(x==y) {
            sol.push_back(x); continue;
        }
        int ans;
        for(int j=20;j>=0;j--)
        {
            if(str[x][j]!=str[y][j])
            {
                x=str[x][j];
                y=str[y][j];
            }
            else ans=str[x][j];
        } sol.push_back(ans);
    }for(int x:sol) cout<<x<<'\n';
    return 0;
}