#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
vector<ll> vahy;
multiset<ll> maxima_centroids;
struct Intervalac{
vector<ll> lenost;
vector<ll> maxima;
};
struct Centroid{
int node;
map<int,int> next_centroid;
map<int,ii> edge_interval;
int listy;
Intervalac intervalac;
multiset<ll> maxima;
map<int,ii> podstromy;
};
vector<Centroid> centroids;
int int_pow(int x, int e){
if (e == 0) return 1;
int m = int_pow(x, e/2);
if (e%2 == 0) return m*m;
else return m*m*x;
}
int dfs(vector<bool>& is_centroid, vector<vector<ii>>& strom, map<int,int>& pocty, int parent, int current){
int res = 1;
for (auto [_, i] : strom[current]){
if (i == parent || is_centroid[i]) continue;
res += dfs(is_centroid, strom, pocty, current, i);
}
pocty[current] = res;
return res;
}
ii dfs2(vector<bool>& is_centroid, vector<vector<ii>>& strom, map<int, ii>& edge_interval, int& found, int parent, int current, vector<int>& indexy_hran, map<int,ii>& podstromy){
ii res = {INT_MAX, INT_MIN};
for (auto [i, j] : strom[current]){
indexy_hran.push_back(i);
if (j == parent || is_centroid[j]) continue;
ii returned = dfs2(is_centroid, strom, edge_interval, found, current, j, indexy_hran, podstromy);
edge_interval[i] = returned;
if (parent == -1){
for (int k : indexy_hran){
podstromy[k] = returned;
}
indexy_hran.clear();
}
res.first = min(res.first, returned.first);
res.second = max(res.second, returned.second);
}
if (res.first == INT_MAX){
res = {found, found};
found++;
}
return res;
}
Intervalac create_intervalac(int n){
Intervalac res;
while(n & (n - 1)) n++;
res.maxima = vector<ll>(2*n, 0);
res.lenost = vector<ll>(2*n, 0);
return res;
}
vector<int> find_centroids(vector<bool>& is_centroid, vector<vector<ii>>& strom, int start){
maxima_centroids.insert(0);
map<int, int> pocty;
dfs(is_centroid, strom, pocty, -1, start);
int current = start;
while (true){
int go_to = -1;
for (auto [_, i] : strom[current]){
if (is_centroid[i]) continue;
if (pocty[i] > pocty[current]/2){
go_to = i;
break;
}
}
if (go_to == -1) break;
pocty[current] -= pocty[go_to];
pocty[go_to] += pocty[current];
current = go_to;
}
if (pocty[current] == 1) return {};
Centroid centr;
centr.node = current;
is_centroid[current] = true;
int found = 0;
vector<int> indexy_hran;
dfs2(is_centroid, strom, centr.edge_interval, found, -1, centr.node, indexy_hran, centr.podstromy);
centr.listy = found;
for (int i = 0; i<strom[centr.node].size(); i++){
centr.maxima.insert(0);
}
centr.intervalac = create_intervalac(centr.listy);
vector<int> sousedi;
for (auto [i, j] : strom[current]){
if (is_centroid[j]) continue;
sousedi.push_back(i);
vector<int> sousedi_sousedu = find_centroids(is_centroid, strom, j);
for (int k : sousedi_sousedu) {
sousedi.push_back(k);
centr.next_centroid[k] = centroids.size()-1;
}
}
centroids.push_back(centr);
return sousedi;
}
ll get_max(Intervalac& inter, int i, int l, int r, int a, int b){
inter.maxima[i] += inter.lenost[i];
if (2*i< inter.lenost.size()){
inter.lenost[2*i] += inter.lenost[i];
inter.lenost[2*i+1] += inter.lenost[i];
}
inter.lenost[i] = 0;
if (l == a && r == b){
return inter.maxima[i];
} else if (r <= (a+b)/2){
return get_max(inter, 2*i, l, r, a, (a+b)/2);
} else if (l >= (a+b)/2){
return get_max(inter, 2*i+1, l, r, (a+b)/2, b);
} else {
return max(get_max(inter, 2*i, l, (a+b)/2, a, (a+b)/2),get_max(inter, 2*i+1, (a+b)/2, r, (a+b)/2, b));
}
}
void vyres_lesnost(Intervalac& inter, int i){
inter.maxima[i] += inter.lenost[i];
if (2*i< inter.lenost.size()){
inter.lenost[2*i] += inter.lenost[i];
inter.lenost[2*i+1] += inter.lenost[i];
}
inter.lenost[i] = 0;
}
void set_val(Intervalac& inter, int i, int l, int r, int a, int b, ll add){
vyres_lesnost(inter, i);
if (l == a && r == b){
inter.lenost[i] = add;
} else if (r <= (a+b)/2){
set_val(inter, 2*i, l, r, a, (a+b)/2, add);
} else if (l >= (a+b)/2){
set_val(inter, 2*i+1, l, r, (a+b)/2, b, add);
} else {
set_val(inter, 2*i, l, (a+b)/2, a, (a+b)/2, add);
set_val(inter, 2*i+1, (a+b)/2, r, (a+b)/2, b, add);
}
if (2*i < inter.lenost.size()){
vyres_lesnost(inter, 2*i);
vyres_lesnost(inter, 2*i+1);
inter.maxima[i] = max(inter.maxima[2*i], inter.maxima[2*i+1]);
}
}
void update(Centroid& centr, ll hrana, ll set_to){
ll maximum_centroidu = 0;
auto it = centr.maxima.end();
it--;
maximum_centroidu += *it;
if (it != centr.maxima.begin()){
it--;
maximum_centroidu += *it;
}
maxima_centroids.erase(maxima_centroids.find(maximum_centroidu));
centr.maxima.erase(centr.maxima.find(get_max(centr.intervalac, 1, centr.podstromy[hrana].first, centr.podstromy[hrana].second+1, 0, centr.intervalac.maxima.size()/2)));
set_val(centr.intervalac, 1, centr.edge_interval[hrana].first, centr.edge_interval[hrana].second+1, 0, centr.intervalac.maxima.size()/2, set_to-vahy[hrana]);
centr.maxima.insert(get_max(centr.intervalac, 1, centr.podstromy[hrana].first, centr.podstromy[hrana].second+1, 0, centr.intervalac.maxima.size()/2));
maximum_centroidu = 0;
it = centr.maxima.end();
it--;
maximum_centroidu += *it;
if (it != centr.maxima.begin()){
it--;
maximum_centroidu += *it;
}
maxima_centroids.insert(maximum_centroidu);
if (centr.next_centroid.find(hrana) != centr.next_centroid.end())
update(centroids[centr.next_centroid[hrana]], hrana, set_to);
}
int main(){
int n,q; cin >> n >> q;
ll w; cin >> w;
vahy.resize(n-1);
vector<vector<ii>> strom(n);
for (int i = 0; i<n-1; i++){
int a,b; cin >> a >> b;
ll c; cin >> c;
vahy[i] = c;
strom[a-1].push_back({i, b-1});
strom[b-1].push_back({i, a-1});
}
vector<bool> is_centroid(n, false);
find_centroids(is_centroid, strom, 0);
for (int i = 0; i<n-1; i++){
update(centroids.back(), i, 2*vahy[i]);
}
ll last = 0;
for (int i = 0 ; i<q; i++){
ll d; cin >> d;
ll e; cin >> e;
update(centroids.back(), (d+last)%(n-1), (e+last)%w);
vahy[(d+last)%(n-1)] = (e+last)%w;
last = *maxima_centroids.rbegin();
cout << last << endl;
}
}
