#include <iostream>
#include <string>
using namespace std;

int main(){
   int n;
   bool num[10];
   for(int i = 0;i < 10;i++) num[i] = true;
   cin >> n;
   for(int a,b,c,d,i = 0;i < n;i++){
      string r;
      cin >> a >> b >> c >> d >> r;
      if(r == "YES"){
         for(int j = 0;j < 10;j++){
            if(j == a || j == b || j == c || j == d) continue;
            else num[j] = false;
         }
      }else num[a] = num[b] = num[c] = num[d] = false;
   }
   for(int i = 0;i < 10;i++){
      if(num[i]){
         cout << i << endl;
         return 0;
      }
   }
}