#include <fstream>
#include <vector>
#define nmax 100002
#define lgmax 25
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

int rmq[lgmax][nmax*2],h[nmax*2],l[nmax*2],f[nmax],lg[nmax*2],k=0;

vector <int> graf[nmax];

void dfs(int nod,int level)
{
    h[++k]=nod;
    l[k]=level;
    f[nod]=k;
    int lg=graf[nod].size();
    for(int i=0;i<lg;i++)
    {
        dfs(graf[nod][i],level+1);
        h[++k]=nod;
        l[k]=level;
    }
}

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

void lca(int x,int y)
{
    if(x>y)
    {
        int au=x;
        x=y;
        y=au;
    }
    x=f[x];
    y=f[y];
    int sol=rmq[lg[y-x+1]][y+1-(1<<lg[y-x+1])];
    if(l[sol]>l[rmq[lg[y-x+1]][x]])
        sol=rmq[lg[y-x+1]][x];
    fout<<h[sol]<<"\n";
}
int main()
{
    int n,m,x,y;
    fin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        fin>>x;
        graf[x].push_back(i);
    }
    dfs(1,0);
    rmqa();
    for(int i=1;i<=m;i++)
        fin>>x>>y,lca(x,y);
    return 0;
}