#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
using ll = long long;
struct seg
{
int N; vector<ll> st, lazy;
seg() {}
void init(int _N) {
N = _N;
st.resize(4 * N, 0);
lazy.resize(4 * N, 0);
}
void prop(int v, int l, int r) {
if(l == r || lazy[v] == 0) return;
st[v * 2] += lazy[v];
st[v * 2 + 1] += lazy[v];
lazy[v * 2] += lazy[v];
lazy[v * 2 + 1] += lazy[v];
lazy[v] = 0;
}
void update(int v, int l, int r, int lo, int hi, ll val) {
if(l > hi || r < lo) return;
if(l >= lo && r <= hi) {
st[v] += val; lazy[v] += val;
return;
}
prop(v, l, r);
update(v * 2, l, (l + r) / 2, lo, hi, val);
update(v * 2 + 1, (l + r) / 2 + 1, r, lo, hi, val);
st[v] = max(st[v * 2], st[v * 2 + 1]);
}
ll query(int v, int l, int r, int lo, int hi) {
if(l > hi || r < lo) return 0;
if(l >= lo && r <= hi) return st[v];
prop(v, l, r);
return max(query(v * 2, l, (l + r) / 2, lo, hi),
query(v * 2 + 1, (l + r) / 2 + 1, r, lo, hi));
}
};
int N, Q; ll W; int S[100005]; seg ST[100005];
int A[100005], B[100005]; ll C[100005];
int par[100005], tin[100005], out[100005];
vector<int> adj[100005]; vector<ll> cur[100005];
vector<pair<int, int>> G[100005];
vector<array<int, 3>> E[100005];
set<pair<ll, int>> ans[100005];
set<pair<ll, int>> best;
int timer; vector<int> K;
bool rem[100005];
int dfs_size(int v, int p) {
S[v] = 1;
for(auto e : adj[v]) {
int u = A[e] ^ B[e] ^ v;
if(u == p || rem[u]) continue;
S[v] += dfs_size(u, v);
}
return S[v];
}
int dfs_centroid(int v, int p, int _N) {
for(auto e : adj[v]) {
int u = A[e] ^ B[e] ^ v;
if(u == p || rem[u]) continue;
if(S[u] * 2 > _N)
return dfs_centroid(u, v, _N);
}
return v;
}
void dfs(int v, int p) {
K.push_back(v); tin[v] = timer++;
for(auto e : adj[v]) {
int u = A[e] ^ B[e] ^ v;
if(u == p || rem[u]) continue;
par[u] = e; dfs(u, v);
}
out[v] = timer - 1;
}
void get(int v, int state) {
auto it = ans[v].rbegin();
ll res = (*it).first;
if(ans[v].size() > 1) {
it++; res += (*it).first;
}
if(state) best.insert({res, v});
else best.erase({res, v});
}
void build(int v) {
int _N = dfs_size(v, v);
if(_N == 1) return;
int centroid = dfs_centroid(v, v, _N);
K.clear(); ST[centroid].init(_N); timer = 0;
par[centroid] = -1; dfs(centroid, centroid);
for(auto u : K) {
if(par[u] == -1) continue;
E[par[u]].push_back({tin[u], out[u], centroid});
ST[centroid].update(1, 0, _N - 1, tin[u], out[u], C[par[u]]);
}
int group = 0;
for(auto e : adj[centroid]) {
int u = A[e] ^ B[e] ^ centroid;
if(rem[u]) continue;
G[centroid].push_back({tin[u], out[u]});
ll calc = ST[centroid].query(1, 0, _N - 1, tin[u], out[u]);
cur[centroid].push_back(calc);
ans[centroid].insert({calc, group++});
}
get(centroid, 1); rem[centroid] = 1;
for(auto e : adj[centroid]) {
int u = A[e] ^ B[e] ^ centroid;
if(rem[u]) continue;
build(u);
}
}
void upd(int I, int O, int D, ll M) {
int lo = 0, hi = G[D].size() - 1, res = 0;
while(lo <= hi) {
int md = (lo + hi) / 2;
if(G[D][md].second < I)
lo = md + 1;
else hi = md - 1, res = md;
}
get(D, 0); ans[D].erase({cur[D][res], res});
ST[D].update(1, 0, ST[D].N - 1, I, O, M);
cur[D][res] = ST[D].query(1, 0, ST[D].N - 1, G[D][res].first, G[D][res].second);
ans[D].insert({cur[D][res], res}); get(D, 1);
}
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> N >> Q >> W;
for(int l = 1; l < N; l++) {
cin >> A[l] >> B[l] >> C[l];
adj[A[l]].push_back(l);
adj[B[l]].push_back(l);
}
build(1); ll last = 0;
for(int l = 0; l < Q; l++) {
int d; ll e; cin >> d >> e;
d = (d + last) % (N - 1) + 1;
e = (e + last) % W;
for(auto u : E[d])
upd(u[0], u[1], u[2], e - C[d]);
C[d] = e; last = (*best.rbegin()).first;
cout << last << "\n";
}
return 0;
}
