int cnt = 10000;

while(cnt--){

bool change = false;

for(int i=1; i<MAXN; i++){

int sum[MAXN];

memset(sum,0,sizeof(sum));

for(int j=0; j<graph[i].size(); j++){

int other = graph[i][j];

for(int k=0; k<MAXN; k++){

sum[k] += own[other][k];

}

}

for(int j=0; j<MAXN; j++){

if(sum[j]>50){

pii t(i, j);

if(seen.find(t)!=seen.end()){

continue;

}

graph[i].push_back(j);

change = true;

seen[t] = 1;

}

}

}

if(change==false)break;

}

for(int i=1; i<MAXN; i++){

sort(graph[i].begin(), graph[i].end());

for(int j=0; j<graph[i].size(); j++){

if(i==graph[i][j])continue;

fout<<i<<" "<<graph[i][j]<<endl;

}

}

fin>>N;

for(int i=0; i<N; i++){

int a,b,c;

fin>>a>>b>>c;

own[a][b] = c;

if(c>50){

pii t(a,b);

if(seen.find(t)==seen.end()){

seen[t] = 1;

graph[a].push_back(b);

}

}

}

for(int i=0; i<MAXN; i++){

graph[i].push_back(i);

}

cout<<"graph is "<<endl;

for(int i=0; i<MAXN; i++){

if(graph[i].size()==0)continue;

for(int j=0; j<graph[i].size(); j++){

cout<<i<<" "<<graph[i][j]<<endl;

}

}

work();

return 0;