#include<cstdio>
#include<vector>
using namespace std;
int euler[300000],depth[300000],rmq[300000][25],log[300000],first[300000],nr=0;
vector<int> v[300000];
void dfs(int nod,int h){
    int dim=v[nod].size(),i;
    nr++;
    euler[nr]=nod;
    depth[nr]=h;
    if(first[nod]==0)
        first[nod]=nr;
    for(i=0;i<dim;i++){
        dfs(v[nod][i],h+1);
        nr++;
        euler[nr]=nod;
        depth[nr]=h;
    }
}
int minimum(int a,int b){
    if(a<b)
        return a;
    return b;
}
void lca(int x,int y){
    int aux;
    if(x>y){
        aux=x;
        x=y;
        y=aux;
    }
    if(depth[rmq[x][log[y-x+1]]]<depth[rmq[y+1-(1<<log[y-x+1])][log[y-x+1]]])
        printf("%d\n",euler[rmq[x][log[y-x+1]]]);
    else
        printf("%d\n",euler[rmq[y+1-(1<<log[y-x+1])][log[y-x+1]]]);
}
int main(){
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    int n,m,i,j,x,y;
    scanf("%d%d",&n,&m);
    for(i=2;i<=n;i++){
        scanf("%d",&x);
        v[x].push_back(i);
    }
    dfs(1,0);
    for(i=1;i<=nr;i++)
        rmq[i][0]=i;
    for(j=1;(1<<j)<=nr;j++)
        for(i=1;i+(1<<j)-1<=nr;i++)
            if(depth[rmq[i][j-1]]<depth[rmq[i+(1<<(j-1))][j-1]])
                rmq[i][j]=rmq[i][j-1];
            else
                rmq[i][j]=rmq[i+(1<<(j-1))][j-1];
    for(i=2;i<=n;i++)
        log[i]=log[i/2]+1;
    for(i=1;i<=m;i++){
        scanf("%d%d",&x,&y);
        lca(first[x],first[y]);
    }
    return 0;
}