#include<fstream>
#include<vector>
using namespace std;

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

const int nmax = 200000;

int n,m,x,y,i,l[nmax],e[nmax],rmq[nmax][20],k=0,lg[nmax],first[nmax];
vector<int> g[nmax];

void dfs(int node, int lev)
{
    e[++k]=node;
    l[k]=lev;
    first[node]=k;
    for (int i=0;i<g[node].size();i++)
    {
        dfs(g[node][i],lev+1);
        e[++k]=node;
        l[k]=lev;
    }
}

void RMQ()
{
    int i,j;
    for (i=2;i<=k;i++) lg[i]=lg[i/2]+1;
    for (i=1;i<=k;i++) rmq[i][0]=i;
    for (j=1;(1<<j)<=k;j++)
        for (i=1;i+(1<<j)-1<=k;i++)
    {
        rmq[i][j]=rmq[i][j-1];
        if (l[rmq[i][j-1]]>l[rmq[i+(1<<(j-1))][j-1]])
            rmq[i][j]=rmq[i+(1<<(j-1))][j-1];
    }
}

int LCA(int x,int y)
{
    int p=first[x], q=first[y];
    if (p>q) swap(p,q);
    int ln=lg[q-p+1];
    return
       (l[rmq[p][ln]]<l[rmq[q-(1<<ln)+1][ln]])? e[rmq[p][ln]] : e[rmq[q-(1<<ln)+1][ln]];
}

int main()
{
    cin>>n>>m;
    for(i=2;i<=n;i++)
    {
        cin>>x;
        g[x].push_back(i);
    }
    dfs(1,0);
    RMQ();
    for (;m--;)
    {
        cin>>x>>y;
        cout<<LCA(x,y)<<"\n";
    }
    return 0;
}