#include <fstream>
using namespace std;
#define maxn 100005
int rmq[20][maxn<<1],euler[maxn<<1],n,m,nod,r,l[maxn<<1],poz[maxn],lg[maxn<<1];

ifstream cin("lca.in");
ofstream cout("lca.out");


void range_minim_querry(){
    for(int i=2; i<=r; i++)
        lg[i]=lg[i>>1]+1;
    for(int i=1; i<=r; i++)
        rmq[0][i]=i;
     for(int i=1;(1<<i)<r;i++)
        for(int j=1;j<=r-(1<<i); j++){
            int L=1<<(i-1);
            rmq[i][j]=rmq[i-1][j];
            if(l[rmq[i-1][j]]>l[rmq[i-1][j+L]])
                rmq[i][j]=rmq[i-1][j+L];
    }
}

void lca(int x,int y){
    int a,b,diff,sh,sol;
    a=poz[x],b=poz[y];
    if(a>b)
        a+=b,b=a-b,a-=b;
    diff=b-a+1;
    sh=diff-(1<<lg[diff]);
    sol=rmq[lg[diff]][a];
    if(l[rmq[lg[diff]][a]]>l[rmq[lg[diff]][a+sh]])
        sol=rmq[lg[diff]][a+sh];
    cout<<euler[sol]<<'\n';
}

void dfs(int no, int k){
        euler[++r]=no;
        l[r]=k;
        poz[no]=r;
         for(int i=0; i<son[1][no]; i++){
            dfs(son[0][no]+i,k+1);
            euler[++r]=no;
            l[r]=k;
         }
}

int main()
{
    cin>>n>>m;
    for(int i=2; i<=n; i++){
        cin>>nod;
        if(!son[0][nod])
            son[0][nod]=i;
        son[1][nod]++;
    }
    dfs(1,0);
    range_minim_querry();
    int x,y;
    for(int i=1; i<=m; i++){
            cin>>x>>y;
            lca(x,y);
    }
    return 0;
}