#include<cstdio>
#include<vector>
#include<algorithm>

using namespace std;

int n,m,to;
int app[100010],nivel[200010],p;
int lg[200010];
int rmq[19][200010];
vector<int> adj[100010];

void fill_euler(int nod,int lvl)
{
    p++;
    app[nod]=p;
    rmq[0][p]=nod;
    rmq[0][0]++;
    nivel[nod]=lvl;
    for(vector<int>::iterator it=adj[nod].begin();it!=adj[nod].end();it++)
    {
        fill_euler(*it,lvl+1);
        p++;
        rmq[0][p]=nod;
        rmq[0][0]++;
    }
}

void build_rmq()
{
    int temp=n;
    while(temp!=0)
    {
        to++;
        temp>>=1;
    }
    for(int i=1;i<=to;i++)
    {
        for(int j=1;;j++)
        {
            if(j+(1<<(i-1))>rmq[i-1][0])
            {
                rmq[i][0]=j-1;
                break;
            }
            if(nivel[rmq[i-1][j]]>nivel[rmq[i-1][j+(1<<(i-1))]])
            {
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
            }
            else
            {
                rmq[i][j]=rmq[i-1][j];
            }
        }
    }
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);

    scanf("%d %d",&n,&m);

    int x,y;
    for(int i=2;i<=n;i++)
    {
        scanf("%d",&x);
        adj[x].push_back(i);
    }
    fill_euler(1,1);
    build_rmq();
    /*for(int i=0;i<=to;i++)
    {
        printf("%d: ",i);
        for(int j=1;j<=rmq[i][0];j++)
        {
            printf("%d ",rmq[i][j]);
        }
        printf("\n");
    }*/
    lg[1]=0;
    for(int i=2;i<=200000;i++)
    {
        lg[i]=lg[i>>1]+1;
    }
    int dist,res;
    for(int i=1;i<=m;i++)
    {
        scanf("%d %d",&x,&y);
        if(app[x]<app[y])
        {
            swap(x,y);
        }
        dist=app[x]-app[y]+1;
        if(nivel[rmq[lg[dist]][app[y]]]>nivel[rmq[lg[dist]][app[x]-(1<<lg[dist])+1]])
        {
            res=rmq[lg[dist]][app[x]-(1<<lg[dist])+1];
        }
        else
        {
            res=rmq[lg[dist]][app[y]];
        }
        printf("%d\n",res);
    }
}