#include <cstdio>
#include <vector>

using namespace std;

const int N=100000+5;
const int LG=19;

int n,t;
vector<int>g[N];
int p[3*N],y=0;
int h[3*N];

int first[N];
int last[N];

int rmq[3*N][LG];
int who[3*N][LG];

int nownr=0;
int nr[N];

int lg[3*N];

inline void dfs(register int nod)
{
    nr[nod]=nownr++;
    if(g[nod].size()==0)
    {
        p[++y]=nod;
    }
    else
    {
        p[++y]=nod;
        for(auto &nou:g[nod])
        {
            h[nou]=h[nod]+1;
            dfs(nou);
            p[++y]=nod;
        }
    }
}


int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    for(register int i=2;i<3*N;i++)
    {
        lg[i]=1+lg[i/2];
    }
    scanf("%d%d",&n,&t);
    register int dad;
    for(register int i=2;i<=n;i++)
    {
        scanf("%d",&dad);
        g[dad].push_back(i);
    }
    dfs(1);
    for(register int i=1;i<=y;i++)
    {
        last[p[i]]=i;
    }
    for(register int i=y;i>=1;i--)
    {
        first[p[i]]=i;
    }
    for(register int i=1;i<=y;i++)
    {
        rmq[i][0]=h[p[i]];
        who[i][0]=p[i];
    }
    for(register int k=1;(1<<k)<=y;k++)
    {
        for(register int i=1;i+(1<<k)-1<=y;i++)
        {
            if(rmq[i][k-1]<rmq[i+(1<<(k-1))][k-1])
            {
                rmq[i][k]=rmq[i][k-1];
                who[i][k]=who[i][k-1];
            }
            else
            {
                rmq[i][k]=rmq[i+(1<<(k-1))][k-1];
                who[i][k]=who[i+(1<<(k-1))][k-1];
            }
        }
    }
    register int a,b,st,dr,k;
    for(register int tc=1;tc<=t;tc++)
    {
        scanf("%d%d",&a,&b);
        if(nr[a]>nr[b])
        {
            swap(a,b);
        }
        st=first[a];
        dr=last[b];
        k=lg[dr-st+1];
        if(rmq[st][k]<rmq[dr-(1<<k)+1][k])
        {
            printf("%d\n",who[st][k]);
        }
        else
        {
            printf("%d\n",who[dr-(1<<k)+1][k]);
        }
    }
    return 0;
}