#include <iostream>
#include <vector>
#include <string>
using namespace std;

int main(){
    string s; cin>>s;
    int n=s.length()/8;

    int repeated=-1;

    bool compet=false;


    for(int i=0; i<n && !compet;++i){
        if(s[i*8]=='1'){ //locomotive
            if(repeated>0) compet=true;
            else{
                repeated=0;
                for(int j=7; s[i*8+j]=='0'; --j) ++repeated;
            }
        }
        else{ //car
            if(repeated==-1) ;
            else if(repeated==0) compet=true;
            else --repeated;
        }
        
    }

    if(repeated>0) compet=true;

    if(compet) cout<<"NO\n";
    else cout<<"YES\n";
}