#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define double long double
#define endl '\n'
#define sz size
#define pb push_back
#define fs first
#define sc second
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
int const INF = LONG_LONG_MAX;

int n, m;
vector<int> adj[100005], h, tour, fir;
vector<bool> mark;

void dfs(int v)
{
    mark[v]=1;
    fir[v]=(int)tour.sz();
    tour.pb(v);
    for(int x:adj[v])
    {
        if(!mark[x])
        {
            h[x]=h[v]+1;
            dfs(x);
            tour.pb(v);
        }
    }
}

void solve()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    cin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        int x;
        cin>>x;
        adj[x].pb(i);
    }

    //creating euler tour of tree, array for first occurence of each vertex in the tree and the height array of the vertices
    mark.assign(n+5, 0);
    h.assign(n+5, 0);
    fir.assign(n+5, 0);
    dfs(1);

    //setting up the sparse table for RMQ and precalc of log2
    int len=(int)tour.sz(), k=log2(len)+1, st[len+5][k], lg[len+5];
    for(int i=0;i<len;i++)
        st[i][0]=tour[i];
    lg[1]=0;
    for(int i=2;i<=len;i++)
        lg[i]=lg[i/2]+1;

    //creating the sparse table
    for(int i=1;i<=k;i++)
    {
        for(int j=0;j+(1<<i)-1<len;j++)
        {
            st[j][i]=st[j][i-1];
            if( h[st[j][i]] > h[st[j+(1<<(i-1))][i-1]] ) {st[j][i]=st[j+(1<<(i-1))][i-1];}
        }
    }

    //answering queries
    for(int i=1;i<=m;i++)
    {
        int l, r;
        cin>>l>>r;
        l=fir[l];
        r=fir[r];
        if(l>r){swap(l, r);}
        int val=lg[r-l+1];
        int ans=st[l][val];
        if(h[st[l][val]] > h[st[r-(1<<val)+1][val]]) {ans=st[r-(1<<val)+1][val];}
        cout<<ans<<endl;
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int tc=1;
    //cin>>tc;
    while(tc--)
    {
        solve();
    }
    return 0;
}