757A - Gotta Catch Em' All - CodeForces Solution

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


int main() {
  int t = 1;
  //cin >> t;
  while (t--) {
        string refe = "Bulbsr";
        map <char , int> k;
        string f;
        cin >> f;
        for(int i = 0; i < f.size();i++){
            k[f[i]]++;
        }
        int mx = f.size();
        for(int i = 0;i < 6;i++){
            mx = min(k[refe[i]] , mx);
        }
        mx = min(mx , k['a']/2);
        mx = min(mx , k['u']/2);
        cout<<mx;
    }
}