#include <fstream>
#include <vector>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int N=100001;
vector<int>H[N];
int apar[N],lev[100*N],nr[100*N],dp[25][100*N],lg[100*N];
int k;
void dfs(int x,int lvl)
{
    lev[++k]=lvl;//lev=>nivelul de pe pozitia k in repr euler;
    nr[k]=x;//nr=>nodul de pe pozitia k in reprz euler;
    apar[x]=k;//apar=>prima aparitie a nodului X in reprz euler;
    for(vector<int>::iterator it=H[x].begin();it!=H[x].end();it++)
    {
        dfs(*it,lvl+1);
        nr[++k]=x;
        lev[k]=lvl;
    }
}
void rmq()
{
    int i,j;
    for(i=2;i<=k;i++) lg[i]=lg[i>>1]+1;
    for(i=1;i<=k;i++) dp[0][i]=i;
    for(i=1;(1<<i)<k;i++)
    {
        for(j=1;j<=k-(1<<i);j++)
        {
            dp[i][j]=dp[i-1][j];
            if(lev[dp[i-1][j]]>lev[dp[i-1][j+(1<<(i-1))]]) dp[i][j]=dp[i-1][j+(1<<(i-1))];
        };
    }
}
int mini(int a,int b)
{
    if(a<=b) return a;
    return b;
}
int minim(int a,int b)
{
    a=apar[a];
    b=apar[b];
    if(a>b) swap(a,b);
    int diff=lg[b-a+1];
    return mini(dp[diff][a],dp[diff][b-(1<<diff)+1]);
}
int main()
{
    int n,m,i,a,b;
    fin>>n>>m;
    for(i=2;i<=n;i++)
    {
        fin>>a;
        H[a].push_back(i);
    }
    dfs(1,0);
    rmq();
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        fout<<nr[minim(a,b)]<<"\n";
    }
}