Bit stuffing

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string data;
    cin>>data;
    string ans="";
    int counter=0;
    for(int i=0; i<data.size(); i++)
    {
        if(data[i]=='1')
        {
            counter++;
            ans+=data[i];
            if(counter==5)
            {
                ans+='0';
                counter=0;
            }
        }
        else
            ans+=data[i],counter=0;
    }
    cout<<ans<<endl;
}