func_code_string: #include <bits/stdc++.h>   using namespace std;   #pragma comment(linker,  /STACK:102400000,102400000 )   const long long INF = 1e18 + 1LL;   const double Pi = acos(-1.0);   const int N = 5e5 + 10, M = 1e3 + 20, mod = 1e9 + 7, inf = 2e9;   vector<int> G[N];   long long dp[N][10], fs[N][10];   long long ans = 0;   int n, k, a, b;   void dfs(int u, int f) {     dp[u][0] = 1;     for (int i = 0; i < G[u].size(); ++i) {       int to = G[u][i];       if (to == f) continue;       dfs(to, u);       for (int j = 0; j <= k; ++j) {         for (int h = 0; h <= k; ++h) {           if (!dp[u][j] || !dp[to][h]) continue;           long long tmp = j + h + 1;           if (tmp % k)             tmp = tmp / k + 1;           else             tmp = tmp / k;           ans += tmp * dp[to][h] * dp[u][j] + fs[u][j] * dp[to][h] +                  fs[to][h] * dp[u][j];         }       }       for (int j = 1; j <= k; ++j)         dp[u][j] += dp[to][j - 1], fs[u][j] += fs[to][j - 1];       dp[u][1] += dp[to][k];       fs[u][1] += fs[to][k] + dp[to][k];     }   }   int main() {     scanf( %d%d , &n, &k);     for (int i = 1; i < n; ++i) {       scanf( %d%d , &a, &b);       G[a].push_back(b);       G[b].push_back(a);     }     dfs(1, 0);     cout << ans << endl;     return 0;   }   