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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    int N,X,Q; cin >> N >> X >> Q;
    int answer = 0;
    while(Q--){
        int M; cin >> M;
        set<int> S;
        int x = 0;
        while(M--){
            int a; cin >> a;
            if(S.count(a)) x = 1;
            S.insert(a);
        }
        if(S.count(X)) x = 2;
        answer += x;
    }
    cout << answer/2.0 << endl;

}