#include <bits/stdc++.h>
using namespace std;
int n, m, d[100000];
vector<int> a[100000], g[100000], was(100000, 0), q, lo(100000, -100000), ans;
void dfs(int v, int p) {
was[v] = 1;
for(int to : g[v])
if(to != p)
if(was[to] == 1) { cout << "No"; exit(0); }
else if(was[to] == 0) dfs(to, v);
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> n >> m;
for(int i = 0; i < n; i++) {
int l; cin >> l; a[i].resize(l);
for(int j = 0; j < l; j++) cin >> a[i][j], a[i][j]--;
if(i) {
int l0 = a[i - 1].size(), p = -1;
for(int j = 0; j < min(l0, l); j++)
if(a[i - 1][j] != a[i][j]) {
p = j; break;
}
if(p == -1 && l0 > l) return cout << "No", 0;
if(p != -1) g[a[i - 1][p]].push_back(a[i][p]), d[a[i][p]]++;
}
}
dfs(0, -1);
for(int i = 0; i < n; i++) if(!d[i]) q.push_back(i);
while(!q.empty()) {
int v = q.back();
q.pop_back();
if(lo[v] > v) return cout << "No", 0;
int z = v;
if(v - 100000 >= lo[v]) {
ans.push_back(v);
z -= 100000;
}
for(int to : g[v]) {
lo[to] = max(lo[to], z);
if(--d[to] == 0)
q.push_back(to);
}
}
cout << "Yes\n" << ans.size() << '\n';
for(int y : ans) cout << y + 1 << ' ';
}
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