#include <fstream>
#include <vector>


using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

int n,m;
vector <int> muchii[100001];
int prim[100001],nivel[100001];
vector <pair<int,int>> euler(1);

pair <int,int> rmq[100001][20];
int best[200001];

void dfs(int nod)
{
    euler.push_back({nivel[nod],nod});
    rmq[euler.size()-1][0]={nivel[nod],nod};
    prim[nod]=euler.size()-1;
    for(auto it:muchii[nod])
    {
        nivel[it]=nivel[nod]+1;
        dfs(it);
        euler.push_back({nivel[nod],nod});
        rmq[euler.size()-1][0]={nivel[nod],nod};
    }
}

int main()
{
    f>>n>>m;
    for(int i=2;i<=n;i++)
    {
        int x;
        f>>x;
        muchii[x].push_back(i);
    }
    nivel[1]=1;
    dfs(1);
    best[2]=1;
    for(int i=3;i<=euler.size()-1;i++)
    {
        best[i]=best[i-1];
        if((1<<(best[i]+1))<=i)
            best[i]++;
    }
    for(int j=1;j<=best[euler.size()-1];j++)
        for(int i=1;i+(1<<j)-1<=euler.size()-1;i++)
            rmq[i][j]=min(rmq[i][j-1],rmq[i+(1<<(j-1))][j-1]);
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        x=prim[x];
        y=prim[y];
        if(x>y)
            swap(x,y);
        g<<min(rmq[x][best[y-x+1]],rmq[y-(1<<best[y-x+1])+1][best[y-x+1]]).second<<'\n';
    }
    return 0;
}