//带权并查集+路径压缩，边权为下面齿轮与上面的转速比，精度也要处理一下。
#include <stdio.h>
#include <string.h>
#include <math.h>
using namespace std;
int father[10010];
double weight[1010];
bool ans;
char word[2][5] = {"No", "Yes"}; 
void initial()
{
    memset(father, 0, sizeof(father));
    ans = true;
}
int find(int x)
{
    if(father[x] == 0)
    {
        weight[x] = 1;
        return x;
    }
    int orif = father[x];
    father[x] = find(father[x]);
    weight[x] *= weight[orif];
    return father[x];
}
bool merge(int u, int v, int x, int y)
{
    int fu = find(u);
    int fv = find(v);
    double ratio = (x /(double) y) / (weight[u] / weight[v]);
    if(fu != fv)
    {
        father[fu] = fv;
        weight[fu] = ratio;
        return true;
    }
    return fabs(ratio - 1) < 0.000000001;
}
int main()
{
    int n, m, t;
    int u, v, x, y;
    scanf("%d", &t);
    for(int k = 1; k <= t; k++)
    {
        initial();
        scanf("%d%d", &n, &m);
        for(int i = 0; i < m; i++)
        {
            scanf("%d%d%d%d", &u, &v, &x, &y);
            ans = ans && merge(u, v, x, y);
        }
        printf("Case #%d: %s\n", k, word[ans]);
    }
    return 0;
}