#include <iostream>
#include <vector>
#include <map>
#define int long long
using namespace std;
const int MAX_SOMMET = 1e5+42, MAX_FEUILLE = (1 << 18), INF = 1e16;
int nbSommet, nbReq, limitePoids;
int ab[MAX_FEUILLE*2][5] = {0};
int aAdd[MAX_FEUILLE*2] = {0};
void unir(int id) {
ab[id][0] = max(ab[id*2][0], ab[id*2+1][0]);
ab[id][1] = min(ab[id*2][1], ab[id*2+1][1]);
ab[id][2] = max(max(ab[id*2][2], ab[id*2+1][2]), ab[id*2][0] - 2 * ab[id*2+1][1]);
ab[id][3] = max(max(ab[id*2][3], ab[id*2+1][3]), ab[id*2+1][0] - 2 * ab[id*2][1]);
ab[id][4] = max(max(ab[id*2][4], ab[id*2+1][4]), max(ab[id*2][2] + ab[id*2+1][0], ab[id*2][0] + ab[id*2+1][3]));
}
void applyOp(int id, int add) {
for(int type = 0; type < 4; type++) {
ab[id][type] += add;
if(type >= 2)
ab[id][type] -= (add * 2);
}
aAdd[id] += add;
}
int applyReq(int deb, int fin, int debReq, int finReq, int id, int val) {
if(deb > finReq || fin < debReq)
return 0;
if(debReq <= deb && fin <= finReq) {
applyOp(id, val);
return 0;
}
applyOp(id*2, aAdd[id]);
applyOp(id*2+1, aAdd[id]);
aAdd[id] = 0;
int milieu = (deb + fin+1) / 2;
applyReq(deb, milieu-1, debReq, finReq, id*2, val);
applyReq(milieu, fin, debReq, finReq, id*2+1, val);
unir(id);
return ab[id][4];
}
int interTemps[MAX_SOMMET][2];
vector<pair<int, int>> adj[MAX_SOMMET];
int prof[MAX_SOMMET] = {0};
vector<int> eulerTour;
void dfs(int sommet, int pere) {
interTemps[sommet][0] = eulerTour.size();
eulerTour.push_back(sommet);
for(auto voisin : adj[sommet]) {
if(voisin.first == pere)
continue;
prof[voisin.first] = prof[sommet] + voisin.second;
dfs(voisin.first, sommet);
eulerTour.push_back(sommet);
}
interTemps[sommet][1] = eulerTour.size()-1;
}
struct Arete{
int deb, fin, cost;
};
Arete listeArete[MAX_SOMMET];
void input() {
cin >> nbSommet >> nbReq >> limitePoids;
for(int arete = 0; arete < nbSommet-1; arete++) {
int u,v,c;
cin >> u >> v >> c;
if(u > v)
swap(u, v);
adj[--u].push_back({--v, c});
adj[v].push_back({u, c});
listeArete[arete] = {u, v, c};
}
}
int last = 0;
int calcReq(int d, int e) {
Arete qui = listeArete[(d + last) % (nbSommet-1)];
int poidsNouv = (e + last) % limitePoids;
int u = qui.deb, v = qui.fin;
if(interTemps[u][0] < interTemps[v][0])
swap(u, v);
int rep = applyReq(0, MAX_FEUILLE-1, interTemps[u][0], interTemps[u][1], 1, poidsNouv - qui.cost);
listeArete[(d + last) % (nbSommet-1)] = {u, v, poidsNouv};
last = rep;
return rep;
}
void printAb() {
for(int i = 1; i < MAX_FEUILLE*2; i++) {
cout << i << " ";
for(int j = 0; j < 5; j++) {
cout << ab[i][j] << " ";
}
cout << endl;
}
}
signed main() {
input();
dfs(0, -1);
for(int i = 0; i < MAX_FEUILLE*2; i++) {
for(int j = 0; j < 5; j++) {
ab[i][j] = -INF;
if(j == 1)
ab[i][j] = INF;
}
}
for(int id = 0; id < eulerTour.size(); id++) {
int posAb = id + MAX_FEUILLE;
ab[posAb][0] = ab[posAb][1] = prof[eulerTour[id]];
ab[posAb][2] = ab[posAb][3] = -prof[eulerTour[id]];
}
for(int noeud = MAX_FEUILLE-1; noeud > 0; noeud--) {
unir(noeud);
}
for(int req = 0; req < nbReq; req++) {
int d,e;
cin >> d >> e;
cout << calcReq(d, e) << "\n";
}
}
