#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,m,x,y,k,in[1145140];
ll sum,s,d;
string a;
queue<char> b;
//ll gcd(ll a,ll b)
//{
//	if(b==0) return a;
//	else gcd(b,a%b);
//}
int main()
{
	cin>>a;
	n=a.length();
	for(int i=0;i<n;i++)
	{
		if(a[i]=='0') b.push('0');
		if(a[i]=='1') b.push('1');
		if(a[i]=='B') b.back()=b.empty();
		
	} 
	while(!b.empty())
	{
		if(b.front()!=b.empty())
		cout<<b.front();
		b.pop();
	}
	return 0;
}

RE了……