#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int long long
namespace dsa
{
struct segmenttreelazy
{
vector<ll> seg,lzy;
int n;
segmenttreelazy(int sz): n(sz){
seg.resize(sz*4,0);
lzy.resize(sz*4,0);
}
void push(int l,int r,int v)
{
if(!lzy[v])return;
seg[v]+=lzy[v];
int lc=v<<1,rc=lc|1;
if(l!=r)lzy[lc]+=lzy[v],lzy[rc]+=lzy[v];
lzy[v]=0;
}
void update(int ql,int qr,ll vl,int l,int r,int v)
{
push(l,r,v);
if(qr<l or r<ql)return;
if(ql<=l and r<=qr)
{
lzy[v]+=vl;
push(l,r,v);
return;
}
int m=(l+r)>>1,lc=v<<1,rc=lc|1;
update(ql,qr,vl,l,m,lc);
update(ql,qr,vl,m+1,r,rc);
seg[v]=max(seg[lc],seg[rc]);
}
void update(int ql,int qr,ll vl){update(ql,qr,vl,0,n-1,1);}
ll get(int ql,int qr,int l,int r,int v)
{
push(l,r,v);
if(qr<l or r<ql)return -1e18;
if(ql<=l and r<=qr)
{
return seg[v];
}
int m=(l+r)>>1,lc=v<<1,rc=lc|1;
return max(get(ql,qr,l,m,lc),get(ql,qr,m+1,r,rc));
}
ll get(int ql,int qr){return get(ql,qr,0,n-1,1);}
};
struct centriod_decomposition{
vector<vector<pair<ll,int>>> ma;
vector<bool> dead;
vector<ll> sz,par,tour,lastwei,in,out;
vector<vector<vector<int>>> orient;
vector<segmenttreelazy> data;
vector<multiset<ll>> mxd;
multiset<ll> pos_ans;
map<pair<int,int>,int> edge;
int n,lim,cen,id=0,counter=0;
centriod_decomposition(int un): n(un)
{
ma.resize(n+1,{});
orient.resize(n+1,{});
in.resize(n+1,{});
out.resize(n+1,{});
dead.resize(n+1,false);
sz.resize(n+1,1);
par.resize(n+1,-1);
lastwei.resize(n+1,0);
in.resize(n+1,0);
out.resize(n+1,0);
}
ll get()
{
return *rbegin(pos_ans);
}
void addedge(int x,int y,int w)
{
lastwei[counter]=w;
edge[{x,y}]=edge[{y,x}]=counter++;
ma[x].push_back({w,y});
ma[y].push_back({w,x});
}
void dfs(int x,int p=0)
{
for(auto it:ma[x])if(it.second^p)dfs(it.second,x),sz[x]+=sz[it.second];
}
int find_centriod(int x)
{
for(auto it:ma[x])
if(sz[it.second]>lim and !dead[it.second])
{
sz[x]-=sz[it.second],sz[it.second]+=sz[x];
return find_centriod(it.second);
}
return x;
}
void euler_tour(int x,int p=0,int xas=-1)
{
for(auto it:ma[x])
if((it.second^p)!=0 and !dead[it.second])
{
in[it.second]=tour.size();
tour.push_back(it.first);
if(xas==-1)euler_tour(it.second,x,it.second);
else euler_tour(it.second,x,xas);
out[it.second]=(int)(tour.size())-1;
int ind=edge[{x,it.second}];
orient[ind].push_back({id,in[it.second],out[it.second]});
}
}
void add_seg(int x,int p=0,int xas=-1)
{
for(auto it:ma[x])
if((it.second^p)!=0 and !dead[it.second])
{
int ind=edge[{x,it.second}];
if(!p)xas=it.second;
orient[ind].back().push_back(in[xas]);
orient[ind].back().push_back(out[xas]);
data.back().update(in[it.second],out[it.second],it.first);
add_seg(it.second,x,xas);
if(!p)
{
mxd.back().insert(data.back().get(in[it.second],out[it.second]));
}
}
}
void decompose(int x=1)
{
lim=sz[x]>>1;
cen=find_centriod(x);
dead[cen]=1;
tour.clear();
euler_tour(cen);
int szt=tour.size();
if(szt>0)
{
data.emplace_back(szt);
mxd.emplace_back();
mxd.back().insert(0);
mxd.back().insert(0);
add_seg(cen);
pos_ans.insert(*rbegin(mxd.back()) + *(++rbegin(mxd.back())));
id++;
}
for(auto it:ma[cen])
if(!dead[it.second])
decompose(it.second);
}
void update(int ed,ll nwei)
{
for(auto igv:orient[ed])
{
int i=igv[0];
int l=igv[3],r=igv[4];
int ul=igv[1],ur=igv[2];
pos_ans.erase(pos_ans.find(*rbegin(mxd[i]) + *(++rbegin(mxd[i]))));
mxd[i].erase(mxd[i].find(data[i].get(l,r)));
data[i].update(ul,ur,nwei-lastwei[ed]);
mxd[i].insert(data[i].get(l,r));
pos_ans.insert(*rbegin(mxd[i]) + *(++rbegin(mxd[i])));
}
lastwei[ed]=nwei;
}
};
};
int32_t main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll n,q,w;
cin>>n>>q>>w;
dsa::centriod_decomposition cd(n);
for(int i=1;i<n;i++)
{
int a,b;ll w1;
cin>>a>>b>>w1;
cd.addedge(a,b,w1);
}
cd.dfs(1);
cd.decompose(1);
ll lst=0;
while(q--)
{
ll d,e;
cin>>d>>e;
d=(d+lst)%(n-1);
e=(e+lst)%w;
cd.update(d,e);
lst=cd.get();
cout<<lst<<endl;
}
}
