#include <cstdio>
#include <vector>

using namespace std;

vector<int> v[100010];
int niv[100010],rmq[20][200010],log[200010],first[100010],nr;

void dfs(int nod,int lev)
{
    niv[nod]=lev;
    rmq[0][++nr]=nod;
    first[nod]=nr;
    for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
    {
        rmq[0][++nr]=nod;
        dfs(*it,lev+1);
    }
}

int lca(int x,int y)
{
    x=first[x];y=first[y];
    if(x>y) swap(x,y);
    int lim=log[y-x+1];
    if(niv[rmq[lim][x]]<niv[rmq[lim][y-(1<<lim)+1]]) return rmq[lim][x];
    else return rmq[lim][y-(1<<lim)+1];
}

int main()
{
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    int n,m,x,y;
    scanf("%d%d",&n,&m);
    for(int i=2;i<=n;i++)
    {
        scanf("%d",&x);
        v[x].push_back(i);
    }
    dfs(1,1);
    for(int i=2;i<=nr;i++) log[i]=log[i/2]+1;
    for(int i=1;i<=log[nr];i++)
    {
        int lim=nr-(1<<i)+1;
        for(int j=1;j<=lim;j++)
            if(niv[rmq[i-1][j]]<niv[rmq[i-1][j+(1<<(i-1))]]) rmq[i][j]=rmq[i-1][j];
            else rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
    }
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        printf("%d\n",lca(x,y));
    }
    return 0;
}