#include <bits/stdc++.h>
#define int long long
using namespace std;
const int Nmax=1e5+5;
class AINT
{
private:
vector<int> aint;
vector<int> lazy;
int n;
public:
AINT(int siz):lazy(4*siz+5,0), aint(4*siz+5,0)
{
n=siz;
}
void propagate(int nod)
{
if(lazy[nod]==0) return;
aint[2*nod]+=lazy[nod];
aint[2*nod+1]+=lazy[nod];
lazy[2*nod]+=lazy[nod];
lazy[2*nod+1]+=lazy[nod];
lazy[nod]=0;
return;
}
int getmax()
{
return aint[1];
}
void update(int nod,int l,int r,int st,int dr,int val)
{
if(st<=l && r<=dr)
{
aint[nod]+=val;
lazy[nod]+=val;
return;
}
int mid=(l+r)/2;
propagate(nod);
if(dr<=mid) update(2*nod,l,mid,st,dr,val);
else if(mid<st) update(2*nod+1,mid+1,r,st,dr,val);
else
{
update(2*nod,l,mid,st,mid,val);
update(2*nod+1,mid+1,r,mid+1,dr,val);
}
aint[nod]=max(aint[2*nod],aint[2*nod+1]);
}
void upd(int l,int r,int val)
{
update(1,0,n-1,l,r,val);
}
};
vector<AINT> aints[Nmax];
multiset<int> bigC[Nmax];
struct edge
{
int u;
int v;
int cost;
};
struct information
{
int tata;
int l;
int r;
};
edge edges[Nmax];
vector<pair<int,int>> g[Nmax];
bool taken[Nmax];
int siz[Nmax],fc[Nmax],frunze[Nmax];
unordered_map<int,information> interv[Nmax];
unordered_map<int,int> nextCentroid[Nmax];
unordered_map<int,int> pozinG[Nmax];
multiset<int> allvals;
void getsizes(int nod,int pr)
{
siz[nod]=1;
for(auto [u,id]:g[nod])
{
if(!taken[u] && u!=pr)
{
getsizes(u,nod);
siz[nod]+=siz[u];
}
}
///cout<<nod<<' '<<pr<<' '<<siz[nod]<<'\n';
}
void getfrunze(int nod,int pr)
{
frunze[nod]=0;
bool ok=0;
for(auto [u,id]:g[nod])
{
if(!taken[u] && u!=pr)
{
getfrunze(u,nod);
frunze[nod]+=frunze[u];
ok=1;
}
}
if(!ok) frunze[nod]++;
}
int getcentroid(int nod,int pr,int tot)
{
for(auto [u,id]:g[nod])
{
if(taken[u] || u==pr) continue;
if(2*siz[u]>tot)
{
return getcentroid(u,nod,tot);
}
}
return nod;
}
void buildaint(int nod,int pr,AINT &cur,int cntfr,int cost,int tata,int centroid)
{
int l=cntfr,r=cntfr+frunze[nod]-1;
cur.upd(l,r,cost);
for(auto [u,id]:g[nod])
{
if(taken[u] || u==pr) continue;
buildaint(u,nod,cur,cntfr,edges[id].cost,tata,centroid);
interv[id][centroid]= {tata,cntfr,cntfr+frunze[u]-1};
cntfr+=frunze[u];
}
return;
}
int getsum(multiset<int>& s)
{
if(s.size()>=2)
{
auto it=s.rbegin();
int sum=(*it);
it++;
sum+=(*it);
return sum;
}
else return (*s.rbegin());
}
int decompBuild(int nod)
{
getsizes(nod,0);
int centroid=getcentroid(nod,0,siz[nod]);
getfrunze(centroid,0);
int cnt=0;
for(auto [u,id]:g[centroid])
{
///cout<<centroid<<' '<<u<<' '<<id<<'\n';
if(taken[u]) continue;
pozinG[u][centroid]=cnt;
cnt++;
AINT cur(frunze[u]);
///cout<<centroid<<' '<<u<<' '<<id<<'\n';
interv[id][centroid]= {u,0,frunze[u]-1};
///cout<<centroid<<' '<<u<<' '<<id<<'\n';
buildaint(u,centroid,cur,0,edges[id].cost,u,centroid);
///cout<<centroid<<' '<<u<<' '<<id<<' '<<cur.getmax()<<'\n';
bigC[centroid].insert(cur.getmax());
aints[centroid].push_back(cur);
///cout<<centroid<<' '<<u<<' '<<id<<'\n';
}
if(!bigC[centroid].empty()) allvals.insert(getsum(bigC[centroid]));
taken[centroid]=1;
for(auto [u,id]:g[centroid])
{
if(taken[u]) continue;
nextCentroid[u][centroid]=decompBuild(u);
}
return centroid;
}
void update(int centroid,int id,int prv,int val)
{
///cout<<centroid<<' '<<id<<' '<<prv<<' '<<val<<'\n';
auto [tata,l,r]=interv[id][centroid];
if(!bigC[centroid].empty())
{
int poz=pozinG[tata][centroid];
int cur=aints[centroid][poz].getmax();
int curval=getsum(bigC[centroid]);
///cout<<curval<<'\n';
allvals.erase(allvals.find(curval));
bigC[centroid].erase(bigC[centroid].find(cur));
///cout<<l<<' '<<r<<'\n';
aints[centroid][poz].upd(l,r,-prv);
aints[centroid][poz].upd(l,r,val);
int nw=aints[centroid][poz].getmax();
bigC[centroid].insert(nw);
///cout<<centroid<<' '<<getsum(bigC[centroid])<<' '<<"UPDATE CENTROID"<<'\n';
allvals.insert(getsum(bigC[centroid]));
}
if(edges[id].u==centroid && edges[id].v==tata) return;
if(edges[id].u==tata && edges[id].v==centroid) return;
int nxt=nextCentroid[tata][centroid];
if(nxt!=0) update(nxt,id,prv,val);
return;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0),cout.tie(0);
int n,q,w;
cin>>n>>q>>w;
for(int i=1; i<n; i++)
{
cin>>edges[i].u>>edges[i].v>>edges[i].cost;
g[edges[i].u].push_back({edges[i].v,i});
g[edges[i].v].push_back({edges[i].u,i});
}
int firstCentroid=decompBuild(1);
int last=0;
///cout<<111<<'\n';
while(q--)
{
int d,e;
cin>>d>>e;
d=(d+last)%(n-1);
e=(e+last)%w;
d++;
///cout<<d<<' '<<e<<'\n';
update(firstCentroid,d,edges[d].cost,e);
edges[d].cost=e;
last=(*allvals.rbegin());
cout<<last<<'\n';
}
return 0;
}
