#include<bits/stdc++.h>
using namespace std;
#define int long long
const int MAX_SOM=300*1000+5;
int nbSom,argDeb;
int val[MAX_SOM],pere[MAX_SOM];
vector<int> listeFils[MAX_SOM];
int posEcri[MAX_SOM];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> memo[MAX_SOM];
void afficher(int pos) {
auto temp=memo[pos];
cout<<memo[pos].size()<<endl;
while (!temp.empty()) {
cout<<temp.top().first<<" "<<temp.top().second<<endl;
temp.pop();
}
cout<<endl;
}
void insere(int pos,int petit) {
while (!memo[petit].empty()) {
memo[pos].push({memo[petit].top().first,memo[petit].top().second});
memo[petit].pop();
}
}
void ajout(int pos,int valAjout) {
memo[pos].push({0,valAjout});
}
void retrait(int pos,int valSuppr) {
//cout<<"!!!!!"<<pos<<" "<<valSuppr<<" "<<gainSur[pos]<<endl;
int gain=-valSuppr,dernDec=0;
while (!memo[pos].empty() and gain<=0) {
dernDec=memo[pos].top().first;
gain+=memo[pos].top().second;
memo[pos].pop();
}
if (gain>0) {
memo[pos].push({dernDec,gain});
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>nbSom>>argDeb;
for (int i=1;i<=nbSom;i++) {
cin>>val[i]>>pere[i];
listeFils[pere[i]].push_back(i);
}
val[0]=argDeb;
int maxFils,valMax;
for (int i=nbSom;i>=0;i--) {
valMax=-1;
maxFils=i;
for (int j:listeFils[i]) {
if (!memo[posEcri[j]].empty() and (int)memo[posEcri[j]].size()>valMax) {
valMax=memo[posEcri[j]].size();
maxFils=j;
}
}
if (valMax==-1) {
posEcri[i]=i;
}
else {
posEcri[i]=posEcri[maxFils];
}
for (int j:listeFils[i]) {
//cout<<"?"<<i<<" "<<j<<endl;
if (j!=maxFils) {
insere(posEcri[i],posEcri[j]);
}
}
if (val[i]>0) {
ajout(posEcri[i],val[i]);
}
else if (val[i]<0) {
retrait(posEcri[i],-val[i]);
}
/*cout<<posEcri[i]<<endl;
afficher(posEcri[i]);*/
}
int argFin=0;
//cout<<argFin<<" "<<-memo[posEcri[0]].top().first+decal[posEcri[0]]<<endl;
while (!memo[posEcri[0]].empty() and argFin>=memo[posEcri[0]].top().first) {
argFin+=memo[posEcri[0]].top().second;
memo[posEcri[0]].pop();
}
cout<<argFin-argDeb<<endl;
return 0;
}
