#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define pi 3.141592653589793238
#define int long long
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);  
cout.tie(0);   

#ifndef ONLINE_JUDGE
    if(fopen("INPUT.txt","r"))
    {
    freopen ("INPUT.txt" , "r" , stdin);
    freopen ("OUTPUT.txt" , "w" , stdout);
    }
#endif  

    string a;
    cin>>a;
    int n=a.length();
    int x=0;
    for(int i=0;i<n;i++)
    {
        if(a[i]=='B')
            x++;
        else
            x--;
    }
    if(x<0)
        cout<<"Yes";
    else
        cout<<"No";
} 

