#include <iostream>
#include <string>
using namespace std;
int main() {
    int i, j, n, b[4], a[10]={};
    string s;
    bool c=true, d;
    cin >> n;
    while (n--) {
        for (i=0; i<4; i++) cin >> b[i];
        cin >> s;
        if (s == "YES") {
            if (c) {
                for (i=0; i<10; i++) {
                    d = true;
                    for (j=0; j<4; j++) {
                        if (i == b[j] && a[i] != -1) {
                            d = false;
                            break;
                        }
                    }
                    if (d) a[i] = -1;
                    else a[i] = 1;
                }
                c = false;
            } else {
                for (i=0; i<10; i++) {
                    d = true;
                    if (a[i] == -1) continue;
                    for (j=0; j<4; j++) {
                        if (i == b[j] && a[i] == 1) d = false;
                    }
                    if (d) a[i] = -1;
                }
            }
        } else if (s == "NO") {
            for (i=0; i<4; i++) {
                a[b[i]] = -1;
            }
        }
    }
    for (i=0; i<10; i++) {
        if (!a[i] || a[i] == 1) {
            cout << i << endl;
            break;
        }
    }
    return 0;
}