#include <bits/stdc++.h>

using namespace std;

const int N = 1e5+1;

long long n, q;
int timp;
int lin[2*N], rmq[20][2*N], lvl[N], lg[2*N], pos[N];
vector<int> mc[N];

bool cmp(int x, int y){
    return lvl[x] < lvl[y];
}

void dfs(int nod, int par){
    lvl[nod] = lvl[par] + 1;
    lin[++timp] = nod;
    pos[nod] = timp;

    for(auto f : mc[nod]){
        dfs(f, nod);
        lin[++timp] = nod;
    }
}

int main()
{
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin>>n>>q;
    for(int i=2;i<=n;++i){
        int x; cin>>x;
        mc[x].push_back(i);
    }

    dfs(1, 0);

    for(int i=1; i <= timp; ++i){
        rmq[0][i] = lin[i];
        if(i>1){
            lg[i] = lg[i/2] + 1;
        }
    }

    for(int e=1; (1<<e)<=timp; ++e){
        for(int i=1; i + (1<<(e-1)) + 1<=timp; ++i){
            rmq[e][i] = min(rmq[e-1][i], rmq[e-1][i+(1<<(e-1))], cmp);
        }
    }

    while (q--)
    {
        int x, y;
        cin>>x>>y;
        x = pos[x];
        y = pos[y];
        if(x>y){
            swap(x, y);
        }
        int e = lg[y-x+1];
        cout << min(rmq[e][x], rmq[e][y-(1<<e)+1], cmp) << '\n';
    }
    
    return 0;
}