#include<bits/stdc++.h>
#define Pmax 18
#define Nmax (1<<18)
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
vector<int>L[Nmax/2];
int AP[Nmax/2],nod[Nmax],nivel[Nmax],RMQ[Pmax][Nmax],Log2[Nmax],n,m,Q;
inline void Read()
{
    f>>n>>Q;
    for(int i=2;i<=n;i++)
    {
        int x;
        f>>x;
        L[x].push_back(i);
    }
}
void Euler(int varf,int niv)
{
    ++m;
    nod[m]=varf;
    nivel[m]=niv;
    for(int i=0;i<L[varf].size();++i)
    {
        Euler(L[varf][i],niv+1);
        ++m;
        nod[m]=varf;
        nivel[m]=niv;
    }
    AP[varf]=m; ///ultima aparitie a varfului "varf" in parcurgerea Euler
}
inline void Build()
{
    int k,x,y;
    Log2[1]=0;
    for(int i=2;i<=m;i++)
        Log2[i]=Log2[i/2]+1;
    ///in RMQ retin pozitiile minimului
    for(int i=1;i<=m;i++)
        RMQ[0][i]=i;
    for(int i=1;(1<<i)<=m;i++)
        for(int j=(1<<i);j<=m;j++)
        {
            k=(1<<(i-1));
            RMQ[i][j]=RMQ[i-1][j];
            x=nivel[RMQ[i-1][j]];
            y=nivel[RMQ[i-1][j-k]];
            if(x>y)
                RMQ[i][j]=RMQ[i-1][j-k];
        }
}
inline void Solve()
{
    int x,y,c,c1,lug,k,sol;
    while(Q--)
    {
        f>>c>>c1;
        x=min(AP[c],AP[c1]);
        y=max(AP[c],AP[c1]);
        lug=(y-x+1);
        k=Log2[lug];
        sol=RMQ[k][y];
        if(nivel[sol]>nivel[RMQ[k][x+(1<<k)-1]])
            sol=RMQ[k][x+(1<<k)-1];
        g<<nod[sol]<<"\n";
    }
}
int main()
{
    Read();
    Euler(1,0);
    Build();
    Solve();
    return 0;
}