#include<iostream>
#include<cstring>
#include<vector>
#include<algorithm>
#include<unordered_map>

using namespace std;

int n,k;
unordered_map<string,vector<pair<string,int>>> g;
unordered_map<string,int> total;
unordered_map<string,bool> st;

int dfs(string ver,vector<string>& nodes)
{
    st[ver]=true;
    nodes.push_back(ver);

    int sum=0;
    for(auto edge:g[ver])
    {
        sum+=edge.second;
        string cur=edge.first;
        if(!st[cur]) sum+=dfs(cur,nodes);
    }

    return sum;
}
int main()
{
    cin>>n>>k;
    while(n--)
    {
        string a,b;
        int t;
        cin>>a>>b>>t;
        g[a].push_back({b,t});
        g[b].push_back({a,t});
        total[a]+=t;
        total[b]+=t;
    }

    vector<pair<string,int>> res;
    for(auto item:total)
    {
        string ver=item.first;
        vector<string> nodes;
        int sum=dfs(ver,nodes)/2;

        if(nodes.size()>2&&sum>k)
        {
            string boss=nodes[0];
            for(string node:nodes)
                if(total[boss]<total[node])
                    boss=node;
            res.push_back({boss,nodes.size()});
        }
    }

    sort(res.begin(),res.end());

    cout<<res.size()<<endl;
    for(auto item:res) cout<<item.first<<' '<<item.second<<endl;



    return 0;
}