#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll m,t,money,a,b,jd[1000005],not_enough_money;
signed main(){
	cin>>m;
	for(ll i=1;i<=m;i++)
	{
		if(jd[i]!=0)money+=jd[i];
		cin>>t>>a;
		if(t==1)money+=a;
		if(t==2){
			if(money>=a)money-=a;
			else not_enough_money++;
		}
		if(t==3){
			cin>>b;
			if(money>=a)money-=a,jd[b]=a;
			else not_enough_money++;
		}
	}
	cout<<not_enough_money;
	return 0;
}