#include <bits/stdc++.h>
using namespace std;
 
int main() {
    int N, K, M;
    cin >> N >> K >> M;
 
    int ans = 0;
    for (int i = 0; i < M; i++) {
        int a, b, c;
        cin >> a >> b >> c;
 
        if (a == N - 1 - K && b == N - 1 - K && c == K) {
            ans++;
        }
    }
 
    cout << ans << endl;
 
    return 0;
}