#include <iostream>

#include <cstdio>

#include <cstring>

#include <map>

using namespace std;

const int N=2*1e3+10;

int n,k,num=0,total=0;

int weight[N]={0},ishead[N],gar[N][N]={0};

bool vis[N]={0};

map<string,int> ma;

map<int,string> mb;

map<int,int> hea;

int stringtoint(string s)

{

    if (ma.find(s)==ma.end())

    {

        ma[s]=num;

        mb[num++]=s;

        return num-1;

    }

    else

    {

        return ma[s];

    }

}

void findmodal(int now,int& head,int& people,int& totwei)

{

    vis[now]=1;

    people++;

    if (weight[now]>weight[head])

    {

        head=now;

    }

    for (int i=0;i<num;i++)

    {

        if (gar[now][i]>0)

        {

            totwei+=gar[now][i];

            gar[i][now]=gar[now][i]=0;

            if (!vis[i])

            {

                findmodal(i,head,people,totwei);

            }

        }

    }

}

int main()

{

//    freopen("in.txt","r",stdin);

    cin>>n>>k;

    string sa,sb;

    int wei;

    for (int i=0;i<n;i++)

    {

        cin>>sa>>sb>>wei;

        int ida=stringtoint(sa);

        int idb=stringtoint(sb);

        weight[ida]+=wei;

        weight[idb]+=wei;

        gar[ida][idb]+=wei;//这里要用+=，不能单单=!

        gar[idb][ida]+=wei;

    }

    for (int i=0;i<num;i++)

    {

        if (vis[i]==0)

        {

            int people=0,head=i,totwei=0;

            findmodal(i,head,people,totwei);

            if (people>2&&totwei>k)

            {

                total++;

                ishead[head]=people;

            }

        }

    }

    cout<<total<<endl;

    map<string,int>::iterator it;

    for (it=ma.begin();it!=ma.end();it++)

    {

        if (ishead[it->second]>0)

        {

            cout<<it->first<<" "<<ishead[it->second]<<endl;

        }

    }

    return 0;

}