#include<bits/stdc++.h>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
#pragma GCC optimize("Ofast")
#define int long long
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int range_rng(int l, int r)
{
return uniform_int_distribution<int>(l,r)(rng);
}
struct muchie
{
int a;
int b;
int c;
};
struct ceva
{
int to;
int w;
int id;
};
struct cmp
{
bool operator()(ceva a, ceva b) const
{
return a.to<b.to;///efectiv orice
}
};
int sz[100005];
muchie edge[100005];
set<ceva,cmp> nodes[100005];
bool blocked[100005];
map<int,int> tin[100005];
map<int,int> revstamp[100005];
map<int,int> tout[100005];
int compsize[100005];
int pathsum[100005];
int res[100005];
vector<pair<int,int>> subarbs[100005];
vector<int> centroids[100005];///in ce centroizi e muchia
multiset<int> rez;
multiset<int> altsetnushdeceamatatea[100005];
int timer;
struct Node
{
int mxval;
int lazy;
};
class AINT
{
public:
int boss;
vector<Node> aint;
void init(int sz)
{
aint.resize(sz*4+5);
}
void build(int l, int r, int val)
{
if (l==r)
{
aint[val].mxval=pathsum[revstamp[boss][l]];
aint[val].lazy=0;
return;
}
int mid;
mid=(l+r)/2;
build(l,mid,val*2);
build(mid+1,r,val*2+1);
aint[val].mxval=max(aint[val*2].mxval,aint[val*2+1].mxval);
aint[val].lazy=0;
}
void prop(int val, int l, int r)
{
if (aint[val].lazy==0)
return;
aint[val].mxval+=aint[val].lazy;
if (l!=r)
{
aint[val*2].lazy+=aint[val].lazy;
aint[val*2+1].lazy+=aint[val].lazy;
}
aint[val].lazy=0;
return;
}
void lazy_update(int l, int r, int val, int qa, int qb, int x)
{
prop(val,l,r);
if (qa<=l && r<=qb)
{
aint[val].lazy+=x;
return;
}
int mid;
mid=(l+r)/2;
if (qa<=mid)
lazy_update(l,mid,val*2,qa,qb,x);
if (qb>mid)
lazy_update(mid+1,r,val*2+1,qa,qb,x);
prop(val*2,l,mid);
prop(val*2+1,mid+1,r);
aint[val].mxval=max(aint[val*2].mxval,aint[val*2+1].mxval);
}
int query(int l, int r, int val, int qa, int qb)
{
prop(val,l,r);
if (qa<=l && r<=qb)
{
return aint[val].mxval;
}
int mid,ans;
ans=-1e18;
mid=(l+r)/2;
if (qa<=mid)
ans=max(ans,query(l,mid,val*2,qa,qb));
if (qb>mid)
ans=max(ans,query(mid+1,r,val*2+1,qa,qb));
return ans;
}
} aint[100005];
void update(int centroid, int node, int x)
{
if (subarbs[centroid].size()==0)
return;
int r,pas,maxie;
r=0;
pas=(1<<16);
while (pas)
{
if (r+pas<subarbs[centroid].size() && subarbs[centroid][r+pas].first<=tin[centroid][node])
r+=pas;
pas=pas/2;
}
maxie=aint[centroid].query(1,compsize[centroid],1,subarbs[centroid][r].first,subarbs[centroid][r].second);
altsetnushdeceamatatea[centroid].erase(altsetnushdeceamatatea[centroid].find(maxie));
aint[centroid].lazy_update(1,compsize[centroid],1,tin[centroid][node],tout[centroid][node],x);
maxie=aint[centroid].query(1,compsize[centroid],1,subarbs[centroid][r].first,subarbs[centroid][r].second);
altsetnushdeceamatatea[centroid].insert(maxie);
res[centroid]=*(prev(altsetnushdeceamatatea[centroid].end()))+*(prev(prev(altsetnushdeceamatatea[centroid].end())));
}
void recalc(int node, int parent)
{
sz[node]=1;
for (auto x : nodes[node])
{
if (x.to!=parent && !blocked[x.to])
{
recalc(x.to,node);
sz[node]+=sz[x.to];
}
}
}
int find_centroid(int node, int parent, int en)
{
for (auto x : nodes[node])
{
if (x.to!=parent && !blocked[x.to] && sz[x.to]>en/2)
return find_centroid(x.to,node,en);
}
return node;
}
void dfs(int node, int parent, int centroid)
{
timer++;
tin[centroid][node]=timer;
revstamp[centroid][timer]=node;
for (auto x : nodes[node])
{
if (x.to!=parent && !blocked[x.to])
{
pathsum[x.to]=pathsum[node]+x.w;
centroids[x.id].push_back(centroid);
dfs(x.to,node,centroid);
}
}
tout[centroid][node]=timer;
}
void decomp(int node, int parent)
{
int centroid;
recalc(node,-1);
centroid=find_centroid(node,-1,sz[node]);
compsize[centroid]=sz[node];
timer=0;
pathsum[centroid]=0;
dfs(centroid,-1,centroid);
aint[centroid].boss=centroid;
aint[centroid].init(sz[node]);
aint[centroid].build(1,sz[node],1);
blocked[centroid]=1;
for (auto x : nodes[centroid])
{
if (x.to!=parent && !blocked[x.to])
{
subarbs[centroid].push_back({tin[centroid][x.to],tout[centroid][x.to]});
decomp(x.to,centroid);
}
}
sort(subarbs[centroid].begin(),subarbs[centroid].end());
}
signed main()
{
/*
ifstream fin("arbore.in");
ofstream fout("arbore.out");
*/
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,q,w,i,j,a,b,c,d,e,last,parent,child,delta,maxie;
cin >> n >> q >> w;
for (i=1; i<=n-1; i++)
{
cin >> a >> b >> c;
nodes[a].insert({b,c,i});
nodes[b].insert({a,c,i});
edge[i]= {a,b,c};
}
pathsum[1]=0;
decomp(1,-1);
for (i=1; i<=n; i++)
{
for (auto x : subarbs[i])
{
maxie=aint[i].query(1,compsize[i],1,x.first,x.second);
altsetnushdeceamatatea[i].insert(maxie);
}
if (!altsetnushdeceamatatea[i].empty())
{
res[i]=*(prev(altsetnushdeceamatatea[i].end()))+*prev((prev(altsetnushdeceamatatea[i].end())));
rez.insert(res[i]);
}
}
last=0;
for (i=1; i<=q; i++)
{
cin >> d >> e;
d=(d+last)%(n-1);
d++;
e=(e+last)%w;
a=edge[d].a;
b=edge[d].b;
for (auto x : centroids[d])
{
///1. elimina rez centroizilor
///2. treci prin centroizi, updateaza subarborii
///3. treci prin centroizi din nou si vezi care sunt cele 2 frunze babane
rez.erase(rez.find(res[x]));
if (tin[x][a]<=tin[x][b] && tout[x][b]<=tout[x][a])
{
child=b;
parent=a;
}
else
{
child=a;
parent=b;
}
delta=e-edge[d].c;
update(x,child,delta);
rez.insert(res[x]);
}
cout << *(prev(rez.end())) << "\n";
last=*(prev(rez.end()));
edge[d].c=e;
}
return 0;
}
