import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

void main() {
    bool[10] yes = true;

    int n = readint();
    for (int i = 0; i < n; i++) {
        auto ss = readln.split;
        if (ss[$ - 1] == "YES") {
            auto ts = ss[0 .. $ - 1].map!(to!int).array;
            ts.sort;
            foreach (a; iota(0, 10).setDifference(ts)) {
                yes[a] = false;
            }
        }
        else {
            foreach (a; ss[0 .. $ - 1].map!(to!int)) {
                yes[a] = false;
            }
        }
    }

    foreach (i, x; yes) {
        if (x) {
            writeln(i);
            break;
        }
    }
}