#include<iostream>

#include<cstdio>

using namespace std;

int main(){

int s,sun,r;

int x[9]

while(x[9]!=0)

{

cin>>s

switch(s)

{

base: 1

if(sun>=1)

{

sun--;

x[r]=x[r]-1;

if(x[r]<=0)

{

r++;

}

}

break;

base: 2

{

sun++;

}

}

}

}