1.1

#include <iostream>
using namespace std;
int main ()
{
int x,p=1,n,r=0;
cin>>x;
do
{
n=x%10;
if(n<5)
{
r=r+n*p;
p=p*10;
}
x=x/10;
}while (x!=0);
cout<<r;
return 0;
}