class Solution {
public:
    long long a=0,sts,n;
    vector<vector<int>>adj;
    vector<int>vis;
 
    long long dfs(int v)
    {
        if(vis[v])return 0;
        vis[v]=1;
        int subt=1;
        for(int&i:adj[v])subt+=dfs(i);
        if(v)a+=(subt+sts-1)/sts;
        return subt;
    }
 
    long long minimumFuelCost(vector<vector<int>>& roads, int seats) {
        n=size(roads)+1;
        adj.resize(n);vis.resize(n);
        sts=seats;
        for(auto&v:roads)
        {
            int i=v[0],j=v[1];
            adj[i].push_back(j);
            adj[j].push_back(i);
        }
        dfs(0);
        return a;
    }
};