func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   istream& operator>>(istream& is, vector<T>& v) {     for (T& x : v) is >> x;     return is;   }   template <class T>   ostream& operator<<(ostream& os, const vector<T>& v) {     if (!v.empty()) {       os << v.front();       for (int i = 1; i < v.size(); ++i) os <<     << v[i];     }     return os;   }   const int N = 100010, L = 17;   int n, ns, nt, cnt;   int dist[N], ds[N], dt[N], ts[N], tt[N];   pair<int, int> cs[N], ct[N], c[N], de[N], des[N], det[N];   int ss[N], st[N];   bool vis[N];   vector<pair<int, int>> g[N];   int prs[N][L], prt[N][L];   bool tag;   void dfs(int u) {     vis[u] = true;     for (const auto& pr : g[u]) {       int v, w;       tie(v, w) = pr;       if (!vis[v]) {         dist[v] = dist[u] + w;         dfs(v);       }     }   }   pair<int, int> decomp(int u) {     if (tag)       for (int i = 1; i < L; ++i) prt[u][i] = prt[prt[u][i - 1]][i - 1];     else       for (int i = 1; i < L; ++i) prs[u][i] = prs[prs[u][i - 1]][i - 1];     pair<int, int> ret(0, u);     vis[u] = true;     for (const auto& pr : g[u]) {       int v, w;       tie(v, w) = pr;       if (!vis[v]) {         if (tag)           prt[v][0] = u;         else           prs[v][0] = u;         dist[v] = dist[u] + w;         auto cur = decomp(v);         cur.first += w;         if (cur > ret) {           if (ret.first) c[++cnt] = ret;           ret = cur;         } else           c[++cnt] = cur;       }     }     return de[u] = ret;   }   int s, t;   int query(int x, int y) {     if (ds[x] > dt[x]) {       if (y >= ns) return ss[ns];       if (ts[x] <= y) return ss[y];       int ret = ss[y] + ds[x] + des[x].first;       for (int i = L - 1; i >= 0; --i)         if (ts[prs[x][i]] > y) x = prs[x][i];       x = prs[x][0];       return ret - ds[x] - min(des[x].first, cs[y].first);     }     if (y >= nt) return st[nt];     if (tt[x] <= y) return st[y];     int ret = st[y] + dt[x] + det[x].first;     for (int i = L - 1; i >= 0; --i)       if (tt[prt[x][i]] > y) x = prt[x][i];     x = prs[x][0];     return ret - dt[x] - min(det[x].first, ct[y].first);   }   int main() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     int q;     cin >> n >> q;     for (int rep = 1; rep < n; ++rep) {       int u, v, w;       cin >> u >> v >> w;       g[u].emplace_back(v, w);       g[v].emplace_back(u, w);     }     dfs(1);     s = max_element(dist + 1, dist + n + 1) - dist;     memset(vis, 0, sizeof(vis));     dist[s] = 0;     auto diam = decomp(s);     t = diam.second;     c[++cnt] = diam;     sort(c + 1, c + cnt + 1, greater<pair<int, int>>());     copy(c + 1, c + cnt + 1, cs + 1);     copy(dist + 1, dist + n + 1, ds + 1);     copy(de + 1, de + n + 1, des + 1);     ns = cnt;     cnt = 0;     memset(vis, 0, sizeof(vis));     dist[t] = 0;     tag = true;     diam = decomp(t);     c[++cnt] = diam;     sort(c + 1, c + cnt + 1, greater<pair<int, int>>());     copy(c + 1, c + cnt + 1, ct + 1);     copy(dist + 1, dist + n + 1, dt + 1);     copy(de + 1, de + n + 1, det + 1);     nt = cnt;     for (int i = 1; i <= ns; ++i) ss[i] = ss[i - 1] + cs[i].first;     for (int i = 1; i <= nt; ++i) st[i] = st[i - 1] + ct[i].first;     fill(ts + 1, ts + n + 1, -1);     ts[s] = 0;     for (int i = 1; i <= ns; ++i) {       int u = cs[i].second;       while (ts[u] == -1) {         ts[u] = i;         u = prs[u][0];       }     }     fill(tt + 1, tt + n + 1, -1);     tt[t] = 0;     for (int i = 1; i <= nt; ++i) {       int u = ct[i].second;       while (tt[u] == -1) {         tt[u] = i;         u = prt[u][0];       }     }     int ans = 0;     while (q--) {       int x, y;       cin >> x >> y;       x = (x + ans - 1) % n + 1;       y = (y + ans - 1) % n + 1;       cout << (ans = query(x, y * 2 - 1)) <<   n ;     }     return 0;   }   