#include <bits/stdc++.h>

using namespace std;

bool symmetry(string s,int l,int r)//l是左边待判断的结点号，r是右边
{
    if(l>=s.length())return true;
    if(r>=s.length()&&s[l]=='#')
        return true;
    if(r>=s.length()&&s[l]!='#')
        return false;
    if((s[l]=='#'&&s[r]!='#')||(s[l]!='#'&&s[r]=='#'))
        return false;
    if(symmetry(s,2*l+1,2*r+2)&&symmetry(s,2*l+2,2*r+1))//左往右，右往左，判断是不是对称；然后左往左，右往右判断；
        return true;
    else return false;
}

int main()
{
    string s;
    cin>>s;
    if(symmetry(s,1,2))
        cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}