#include <iostream>
#include <vector>
#include <fstream>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

const int nmax=100005;

int euler[2*nmax], lev[nmax], first[nmax], log[2*nmax], rmq[18][2*nmax], nod[18][2*nmax];
int cnt, aux, n, m, i, j, x, y, node;

vector <int> v[nmax];

void dfs(int x)
{
    euler[++cnt]=x;
    first[x]=cnt;
    for(int i=0;i<v[x].size();i++)
    {
        lev[v[x][i]]=lev[x]+1;
        node=v[x][i];
        dfs(node);
        euler[++cnt]=x;
    }
}

int lca(int x, int y)
{
    x=first[x];
    y=first[y];
    if(x>y)
    {
        aux=x;
        x=y;
        y=aux;
    }
    int dif=y-x+1;
    int p=log[dif];
    if(rmq[p][x]<rmq[p][y-(1<<p)+1])
        return nod[p][x];
    return nod[p][y-(1<<p)+1];
}

int main()
{
    fin>>n>>m;
    for(i=2;i<=n;i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
    for(i=2;i<=2*nmax;i++)
        log[i]=log[i/2]+1;
    dfs(1);
    for(i=1;i<=cnt;i++)
    {
        rmq[0][i]=lev[euler[i]];
        nod[0][i]=euler[i];
    }
    for(i=1;(1<<i)<=cnt;i++)
    {
        for(j=1;j+(1<<i)<=cnt;j++)
        {
            if(rmq[i-1][j]<rmq[i-1][j+(1<<(i-1))])
            {
                rmq[i][j]=rmq[i-1][j];
                nod[i][j]=nod[i-1][j];
            }
            else
            {
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
                nod[i][j]=nod[i-1][j+(1<<(i-1))];
            }
        }
    }
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        fout<<lca(x,y)<<'\n';
    }
    return 0;
}