#include <fstream>
#include <algorithm>
using namespace std;
int n;
float all[12];
string color, type;
int main(){
    ifstream fin("input.txt");
    ofstream fout("output.txt");
    fin>>n;
    for(int i=0;i<n;i++){
        fin>>color>>type;
        if (color=="white"){
            if(type=="pawn"){
                all[0]+=0.125;
                continue;
            }
            if(type=="rook"){
                all[1]+=0.5;
                continue;
            }
            if(type=="bishop"){
                all[2]+=0.5;
                continue;
            }
            if(type=="knight"){
                all[3]+=0.5;
                continue;
            }
            if(type=="king"){
                all[4]++;
                continue;
            }
            if(type=="queen"){
                all[5]++;
                continue;
            }
        }
        else if (color=="black"){
            if(type=="pawn"){
                all[6]+=0.125;
                continue;
            }
            if(type=="rook"){
                all[7]+=0.5;
                continue;
            }
            if(type=="bishop"){
                all[8]+=0.5;
                continue;
            }
            if(type=="knight"){
                all[9]+=0.5;
                continue;
            }
            if(type=="king"){
                all[10]++;
                continue;
            }
            if(type=="queen"){
                all[11]++;
                continue;
            }
        }
    }
    sort(all,all+12);
    fout<<(int)all[0];
}