#include <cstdio>
#include <cstring>
#include <queue>
#include <stack>
#include <vector>
#include <algorithm>
#define MAXN 16000+10
#define MAXM 40000+10
using namespace std;
struct Edge
{
    int from, to, next;
};
Edge edge[MAXM];
int head[MAXN], edgenum;
int low[MAXN], dfn[MAXN];
int sccno[MAXN], scc_cnt;
int dfs_clock;
stack<int> S;
bool Instack[MAXN];
int N, M;
void init()
{
    edgenum = 0;
    memset(head, -1, sizeof(head));
}
void addEdge(int u, int v)
{
    Edge E = {u, v, head[u]};
    edge[edgenum] = E;
    head[u] = edgenum++;
}
void getMap()
{
    int a, b;
    while(M--)
    {
        scanf("%d%d", &a, &b);
        if(a > 0 && b > 0)//a 和 b 至少一个留下
        {
            addEdge(b + N, a);
            addEdge(a + N, b);
        }
        else if(a > 0 && b < 0)//a留 和 b走 至少成立一个
        {
            b = -b;
            addEdge(b, a);
            addEdge(a + N, b + N);
        }
        else if(a < 0 && b > 0)//a走 和 b留 至少成立一个
        {
            a = -a;
            addEdge(b + N, a + N);
            addEdge(a, b);
        }
        else//a 和 b 至少走一个
        {
            a = -a, b = -b;
            addEdge(b, a + N);
            addEdge(a, b + N);
        }
    }
}
void tarjan(int u, int fa)
{
    int v;
    low[u] = dfn[u] = ++dfs_clock;
    S.push(u);
    Instack[u] = true;
    for(int i = head[u]; i != -1; i = edge[i].next)
    {
        v = edge[i].to;
        if(!dfn[v])
        {
            tarjan(v, u);
            low[u] = min(low[u], low[v]);
        }
        else if(Instack[v])
            low[u] = min(low[u], dfn[v]);
    }
    if(low[u] == dfn[u])
    {
        scc_cnt++;
        for(;;)
        {
            v = S.top();S.pop();
            Instack[v] = false;
            sccno[v] = scc_cnt;
            if(v == u) break;
        }
    }
}
void find_cut(int l, int r)
{
    memset(low, 0, sizeof(low));
    memset(dfn, 0, sizeof(dfn));
    memset(sccno, 0, sizeof(sccno));
    memset(Instack, false, sizeof(Instack));
    dfs_clock = scc_cnt = 0;
    for(int i = l; i <= r; i++)
        if(!dfn[i]) tarjan(i, -1);
}
vector<int> G[MAXN];
int in[MAXN];
void suodian()//反向建图
{
    for(int i = 1; i <= scc_cnt; i++) G[i].clear(), in[i] = 0;
    for(int i = 0; i < edgenum; i++)
    {
        int u = sccno[edge[i].from];
        int v = sccno[edge[i].to];
        if(u != v)
            G[v].push_back(u), in[u]++;
    }
}
int k = 1;
int fp[MAXN];//建立SCC到SCC的映射
int color[MAXN];//染色
void toposort()
{
    memset(color, -1, sizeof(color));
    queue<int> Q;
    for(int i = 1; i <= scc_cnt; i++) if(in[i] == 0) Q.push(i);
    while(!Q.empty())
    {
        int u = Q.front();
        Q.pop();
        if(color[u] == -1)
        {
            color[u] = 1;
            color[fp[u]] = 0;
        }
        for(int i = 0; i < G[u].size(); i++)
        {
            int v = G[u][i];
            if(--in[v] == 0)
                Q.push(v);
        }
    }
}
void solve()
{
    printf("Case %d: ", k++);
    for(int i = 1; i <= N; i++)
    {
        if(sccno[i] == sccno[i+N])
        {
            printf("No\n");
            return ;
        }
        else
        {
            fp[sccno[i]] = sccno[i+N];
            fp[sccno[i+N]] = sccno[i];
        }
    }
    printf("Yes\n");
    suodian();
    toposort();//反向拓扑
    int ans = 0;
    for(int i = 1; i <= N; i++)
    {
        if(color[sccno[i]] == 1)
           ans++;
    }
    printf("%d", ans);
    for(int i = 1; i <= N; i++)
    {
        if(color[sccno[i]] == 1)
            printf(" %d", i);
    }
    printf("\n");
}
int main()
{
    int t;
    scanf("%d", &t);
    while(t--)
    {
        scanf("%d%d", &M, &N);
        init();
        getMap();
        find_cut(1, 2*N);
        solve();
    }
    return 0;
}