The given conditions can be checked by finding the positions of B, K, and R in \(S\).

This can be easily inspected by managing the arrays that stores the positions of occurrences of each character. See also the sample code.

Sample code (C++):

#include <bits/stdc++.h>
using namespace std;

int main() {
    const int n = 8;
    string s;
    cin >> s;
    map<char, vector<int>> mp;
    for(int i = 0; i < n; i++) {
        mp[s[i]].push_back(i);
    }
    bool ok = 1;
    ok &= mp['B'][0] % 2 != mp['B'][1] % 2;
    ok &= mp['R'][0] < mp['K'][0] and mp['K'][0] < mp['R'][1];
    cout << (ok ? "Yes\n" : "No\n");
}