// YOLO ATTEMPT 2015

#include<iostream>
#include<vector>
#include<cstdio>

using namespace std;
typedef int var;

var _max, child, other, sol;
var Parent[150000], Viz[150000], Cost[150000];
var Empty[150000], Ee = 0;

void clrEmpty() {
    for(var i=0; i<Ee; i++) {
        Viz[Empty[i]] = 0;
    }
    Ee = 0;
}

bool adv(var &node) {
    if(!node) return true;
    if(Viz[node]) return false;
    Viz[node] = 1;
    Empty[Ee++] = node;
    node = Parent[node];
    return true;
}

var getLca(var a, var b) {
    clrEmpty();
    while(true) {
        if(!adv(a)) return a;
        if(!adv(b)) return b;
    }
}

void update(var &a, var &b, var &lca) {
    for(var node = a; node != lca; node = Parent[node]) {
        if(_max < Cost[node]) {
            _max = Cost[node];
            child = a;
            sol = node;
            other = b;
        }
    }
}

void getMax(var a, var b) {
    _max = -1, sol = -1;
    var lca = getLca(a, b);

    update(a, b, lca);
    update(b, a, lca);
}

void makeRoot(var node) {
    if(Parent[node]) {
        makeRoot(Parent[node]);
        Parent[Parent[node]] = node;
        Parent[node] = 0;
    }
}



#define DIM 100000
char buff[DIM];
var poz;
void Read(var &a) {
    while(!isdigit(buff[poz]))
        if(++poz == DIM)
            cin.read(buff, DIM), poz=0;
    a = 0;
    while(isdigit(buff[poz])) {
        a = a * 10 + buff[poz] - '0';
        if(++poz == DIM)
            cin.read(buff, DIM), poz=0;
    }
}

var n;
void dump() {
    for(var i=1; i<=n; i++) {
        cerr << Parent[i] << " ";
    }
    cerr << endl;
}

int main() {
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    cin.read(buff, DIM);

    var a, b, c;
    Read(n);
    Read(q);
    long long total = 0;

    for(var i=2; i<=n; i++) {
        Read(a);// Read(b);

        Parent[i] = a;
        Cost[i] = b;
        total += b;
    }
    Cost[1] = -1;

    var q;
    //Read(q);
    while(q--) {
        Read(a); Read(b);// Read(c);
        cout << getLca(a, b) << '\n';
        continue;

        getMax(a, b);
        if(_max > c) {
            total -= (_max - c);
            Parent[sol] = 0; // Stergem muchia sol -> Parent[sol]
            makeRoot(child); // Facem nodul din subarborele lui sol radacina
            Parent[child] = other; // Il legam de celalalt
            Cost[child] = c;
        }

        // dump();
        cout << total << "\n";
    }

    return 0;
}