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

template<typename T>
void fin(T a){
  cout<<a<<endl;
  exit(0);
}

signed main(){
    vector<int> v(10,1);
    int n;cin>>n;
    while(n--){
        int a,b,c,d;cin>>a>>b>>c>>d;string s;cin>>s;
        if(s[0]=='N')v[a]=v[b]=v[c]=v[d]=0;
    }
    for(int i=0;i<10;i++)if(v[i])fin(i);
}