#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k, i, j, x, b = 0;
  cin >> n >> m;
  for (i = 1; i <= m; i++) {
    int a[100000] = {0}, k1 = 0;
    cin >> k;
    for (j = 0; j < k; j++) {
      cin >> x;
      if (a[abs(x)] == 2 && x > 0 || a[abs(x)] == 1 && x < 0) {
        k1++;
      }
      if (x > 0)
        a[x] = 1;
      else
        a[abs(x)] = 2;
    }
    if (k1 == 0) {
      b = 1;
    }
  }
  if (b == 1)
    cout << "Yes";
  else
    cout << "No";
}
