#include <bits/stdc++.h>
#define int long long
using namespace std;
const int nmax = 1e5;
struct Edge
{
int x, y, c;
};
int n, q, w;
Edge e[nmax + 5];
vector<pair<int,int>> G[nmax + 5];
int l[nmax + 5];
int t[nmax + 5];
int p[nmax + 5], u[nmax + 5];
int r[nmax + 5];
pair<int,int> ai[4 * nmax + 5];
int lazy[4 * nmax + 5];
pair<int,int> Merge(pair<int,int> a, pair<int,int> b)
{
if(a > b)
{
return a;
}
return b;
}
void init(int nod, int a, int b)
{
if(a == b)
{
ai[nod].second = l[a];
return;
}
int mij = (a + b) >> 1;
init(nod * 2, a, mij);
init(nod * 2 + 1, mij + 1, b);
ai[nod] = Merge(ai[nod * 2], ai[nod * 2 + 1]);
}
void propag(int nod)
{
if(lazy[nod] == 0)
{
return;
}
ai[nod * 2].first += lazy[nod];
ai[nod * 2 + 1].first += lazy[nod];
lazy[nod * 2] += lazy[nod];
lazy[nod * 2 + 1] += lazy[nod];
lazy[nod] = 0;
}
void update(int ua, int ub, int val, int nod, int a, int b)
{
if(ua <= a && ub >= b)
{
ai[nod].first += val;
lazy[nod] += val;
return;
}
propag(nod);
int mij = (a + b) >> 1;
if(ua <= mij)
{
update(ua, ub, val, nod * 2, a, mij);
}
if(ub > mij)
{
update(ua, ub, val, nod * 2 + 1, mij + 1, b);
}
ai[nod] = Merge(ai[nod * 2], ai[nod * 2 + 1]);
}
pair<int,int> query(int qa, int qb, int nod, int a, int b)
{
if(qa <= a && qb >=b)
{
return ai[nod];
}
propag(nod);
int mij = (a + b) >> 1;
if(qa <= mij && qb > mij)
{
return Merge(query(qa, qb, nod*2, a, mij), query(qa, qb, nod*2+1, mij+1, b));
}
if(qa <= mij)
{
return query(qa, qb, nod*2, a, mij);
}
return query(qa, qb, nod*2+1, mij+1, b);
}
bool subtask2()
{
#ifdef home
return false;
#endif // home
return (n <= 5000 && q <= 5000);
}
bool subtask3()
{
for(int i=1; i<n; i++)
{
if(e[i].x != 1 && e[i].y != 1)
{
return false;
}
}
return true;
}
bool subtask4()
{
for(int i=1; i<n; i++)
{
if(e[i].y == 2 * e[i].x || e[i].y == 2 * e[i].x + 1)
{
continue;
}
if(e[i].x == 2 * e[i].y || e[i].x == 2 * e[i].y + 1)
{
continue;
}
return false;
}
return true;
}
int dfs(int nod, int dad = 0)
{
l[nod] = 0;
vector<int> lst;
int rez = 0;
for(auto it : G[nod])
{
if(it.first == dad)
{
continue;
}
rez = max(rez, dfs(it.first, nod));
lst.push_back(l[it.first] + e[it.second].c);
l[nod] = max(l[nod], l[it.first] + e[it.second].c);
}
sort(lst.begin(), lst.end(), greater<int>());
if(lst.size() == 0)
{
r[nod] = rez;
return rez;
}
if(lst.size() == 1)
{
rez = max(rez, lst.front());
r[nod] = rez;
return rez;
}
rez = max(rez, lst[0] + lst[1]);
r[nod] = rez;
return rez;
}
void solve2()
{
int last = 0;
for(int i=1; i<=q; i++)
{
int edge, val;
cin>>edge>>val;
edge = (edge + last) % (n - 1) + 1;
val = (val + last) % w;
e[edge].c = val;
last = dfs(1);
cout<<last<<'\n';
}
}
void solve3()
{
int last = 0;
multiset<int, greater<int>> s;
for(int i=1; i<n; i++)
{
s.insert(e[i].c);
}
for(int i=1; i<=q; i++)
{
int edge, val;
cin>>edge>>val;
edge = (edge + last) % (n - 1) + 1;
val = (val + last) % w;
auto it = s.lower_bound(e[edge].c);
s.erase(it);
s.insert(val);
e[edge].c = val;
last = 0;
it = s.begin();
last += *it;
++it;
last += *it;
cout<<last<<'\n';
}
}
void solve4()
{
int last = 0;
dfs(1);
multiset<int, greater<int>> s;
for(int i=1; i<=n; i++)
{
s.insert(r[i]);
}
for(int i=1; i<=q; i++)
{
int edge, val;
cin>>edge>>val;
edge = (edge + last) % (n - 1) + 1;
val = (val + last) % w;
e[edge].c = val;
int nod = min(e[edge].x, e[edge].y);
while(nod != 0)
{
auto er = s.lower_bound(r[nod]);
s.erase(er);
l[nod] = 0;
vector<int> lst;
for(auto it : G[nod])
{
if(it.first == nod / 2)
{
continue;
}
lst.push_back(l[it.first] + e[it.second].c);
l[nod] = max(l[nod], l[it.first] + e[it.second].c);
}
sort(lst.begin(), lst.end(), greater<int>());
if(lst.size() == 0)
{
r[nod] = 0;
}
else if(lst.size() == 1)
{
r[nod] = lst.front();
}
else
{
r[nod] = lst[0] + lst[1];
}
s.insert(r[nod]);
nod /= 2;
}
auto it = s.begin();
last = *it;
cout<<last<<'\n';
}
}
int cnt = 0;
void euler(int nod, int dad = 0, int root = 0)
{
p[nod] = (++cnt);
l[cnt] = nod;
t[nod] = dad;
r[nod] = root;
for(auto it : G[nod])
{
if(it.first == dad)
{
continue;
}
if(dad == 0)
{
euler(it.first, nod, it.first);
}
else
{
euler(it.first, nod, root);
}
}
u[nod] = cnt;
}
void solve5()
{
euler(1);
init(1, 1, n);
for(int i=1; i<n; i++)
{
if(e[i].y == t[e[i].x])
{
swap(e[i].x, e[i].y);
}
update(p[e[i].y], u[e[i].y], e[i].c, 1, 1, n);
}
int last = 0;
for(int i=1; i<=q; i++)
{
int edge, val;
cin>>edge>>val;
edge = (edge + last) % (n - 1) + 1;
val = (val + last) % w;
update(p[e[edge].y], u[e[edge].y], val - e[edge].c, 1, 1, n);
e[edge].c = val;
pair<int,int> Max1 = ai[1];
pair<int,int> Max2 = {0, 0};
if(p[r[Max1.second]] != 2)
{
Max2 = Merge(Max2, query(2, p[r[Max1.second]] - 1, 1, 1, n));
}
if(u[r[Max1.second]] != n)
{
Max2 = Merge(Max2, query(u[r[Max1.second]] + 1, n, 1, 1, n));
}
last = Max1.first + Max2.first;
cout<<last<<'\n';
}
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
#ifdef home
freopen("nr.in","r",stdin);
freopen("nr.out","w",stdout);
#endif // home
cin>>n>>q>>w;
for(int i=1; i<n; i++)
{
cin>>e[i].x>>e[i].y>>e[i].c;
G[e[i].x].push_back({e[i].y, i});
G[e[i].y].push_back({e[i].x, i});
}
if(subtask2())
{
solve2();
return 0;
}
if(subtask3())
{
solve3();
return 0;
}
if(subtask4())
{
solve4();
return 0;
}
solve5();
return 0;
}
