#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define debug(x) cout << #x << "= " << x << ", "
#define ll long long
#define fast ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define SZ(x) (int) x.size()
#define wall cout << endl;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 1e2 + 10;
int n , w , q , st[maxn] , fn[maxn] , dis[maxn] , par[maxn];
vector <pair<int , int>> adj[maxn];
vector <int> trav;
void dfs(int v , int p = -1)
{
st[v] = SZ(trav);
trav.pb(dis[v]);
for(auto u : adj[v]) if(u.F != p)
{
par[u.F] = v;
dis[u.F] = dis[v] + u.S;
dfs(u.F , v);
trav.pb(dis[v]);
}
fn[v] = SZ(trav);
}
void Add(int v , int val)
{
for(int i = st[v] ; i < fn[v] ; i++) trav[i] += val;
}
int solve()
{
int res = 0;
for(int i = 0 ; i < SZ(trav) ; i++)
for(int j = i ; j < SZ(trav) ; j++)
for(int k = j ; k < SZ(trav) ; k++)
res = max(res , trav[i] + trav[k] - 2 * trav[j]);
return res;
}
int32_t main()
{
fast;
cin >> n >> q >> w;
vector <pair<pair<int , int> , int>> edges;
for(int i = 0 ; i < n -1 ; i++)
{
int v , u , c; cin >> v >> u >> c;
adj[v].pb({u , c}); adj[u].pb({v , c});
edges.pb({{u , v} , c});
}
dfs(1);
int last = 0;
while(q--)
{
int id , val; cin >> id >> val;
id = (id + last) % (n - 1);
val = (val + last) % w;
auto u = edges[id];
int v = u.F.F;
if(par[v] != u.F.S) v = u.F.S;
int tmp = (val - u.S);
Add(v , tmp);
last = solve();
edges[id].S = val;
cout << last << '\n';
}
return 0;
}
