#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
int tA = 0, tC = 0, tB = 0, tK1 = 0, tK2 = 0, tK3 = 0, tK4 = 0;

queue<int> q;
void K4(char ch){
    tC = tK4 + 4;
}
void K3(char ch){
    if (ch == 'B'){
        tB = tK3 + 2;
    }
    else{
        tC = tK3 + 4;
    }
}
void K2(char ch){
    tB = tK2 + 2;
}
void K1(char ch){
    if (ch == 'B'){
        q.push(6);
    }
    else{
        q.push(12);
    }
    int tmp = q.front();
    if (tK3 <= tK1){
        if (tmp == 6){
            tK3 = tK1 + 4;
            K3('B');
        }
        else{
            tK3 = tK1 + 8;
            K3('C');
        }
        q.pop();
    }
    else if (tmp == 6 && tK2 <= tK1){
        tK2 = tK1 + 6;
        K2('B');
        q.pop();
    }
    else if (tmp == 12 && tK4 <= tK1){
        tK4 = tK1 + 12;
        K4('C');
        q.pop();
    }
    else {
        if (tmp == 6){
            tK1 = min(tK3, tK2);
        }
        else tK1 = min(tK3, tK4);
    }
}
void A(char ch){
    if (ch == 'B'){
        tK1 += 1;
    }
    else tK1 += 2;
    K1(ch);
}
int main(){
    for (int i = 0; i < 16; ++i){
        char ch;
        cin >> ch;
        A(ch);
    }
    while(!q.empty()){
        int tmp = q.front();
        if (tK3 <= tK1){
            if (tmp == 6){
                tK3 = tK1 + 4;
                K3('B');
            }
            else{
                tK3 = tK1 + 8;
                K3('C');
            }
            q.pop();
        }
        else if (tmp == 6 && tK2 <= tK1){
            tK2 = tK1 + 6;
            K2('B');
            q.pop();
        }
        else if (tmp == 12 && tK4 <= tK1){
            tK4 = tK1 + 12;
            K4('C');
            q.pop();
        }
        else {
            if (tmp == 6){
                tK1 = min(tK3, tK2);
            }
            else tK1 = min(tK3, tK4);
        }
    }
    cout << max(tB, tC);
    return 0;
}