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

set <string> S;

int main() {
    ifstream in ("input.txt");
    ofstream out ("output.txt");

    int N;
    in >> N;
    int sol = 0;
    for (int i=0; i<N; i++) {
        string a, b, c;
        string op1, op2;
        in >> a >> op1 >> b >> op2 >> c;

        S.insert (a);
        if (S.count(b)==0 && S.count(c)==0) sol++;
    }
    out << sol;
}