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| #include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <vector>
#include <map>
#include <utility>
#ifdef XLor
#define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
void err() { std::cout << std::endl; }
template<typename T, typename...Args>
void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
#else
#define dbg(...)
#endif
#define ms(a,b) memset(a,b,sizeof(a))
using namespace std;
typedef long long ll;
typedef pair<int,int> PII;
const int mod = 998244353;
const int inf = 1 << 30;
const int maxn = 100000 + 5;
inline int add(int x, int y) {
x += y;
return x >= mod ? x -= mod : x;
}
inline int sub(int x, int y) {
x -= y;
return x < 0 ? x += mod : x;
}
inline int mul(int x, int y) {
return 1ll * x * y % mod;
}
inline int qpow(int x, ll n) {
int r = 1;
while (n > 0) {
if (n & 1) r = 1ll * r * x % mod;
n >>= 1; x = 1ll * x * x % mod;
}
return r;
}
inline int inv(int x) {
return qpow(x, mod - 2);
}
int n, m, ans[maxn];
vector<int> edge[maxn * 2], bcc[maxn];
map<int,int> ew[maxn];
int cnt;
namespace cactus {
struct E {
int to, nxt;
} e[maxn * 2];
int head[maxn], ecnt;
void adde(int u, int v) {
e[++ecnt] = {v, head[u]};
head[u] = ecnt;
}
int tot, dfn[maxn], fa[maxn];
bool ring[maxn];
void clear(int n) {
cnt = ecnt = tot = 0;
for (int i = 1; i <= n; i++) {
head[i] = dfn[i] = ans[i] = 0;
}
}
void dfs(int u, int f) {
dfn[u] = ++tot;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].to;
if (v == f) continue;
if (!dfn[v]) {
fa[v] = u; ring[u] = false;
dfs(v, u);
if (!ring[u]) {
edge[u].push_back(v); edge[v].push_back(u);
}
} else if (dfn[v] < dfn[u]) {
cnt++; int rt = cnt + n;
bcc[cnt].clear();
edge[rt].push_back(v);
edge[v].push_back(rt);
bcc[cnt].push_back(v);
for (int x = u; x != v; x = fa[x]) {
ring[x] = true;
bcc[cnt].push_back(x);
edge[rt].push_back(x);
edge[x].push_back(rt);
}
ring[v] = true;
}
}
}
void build() {
dfs(1, 0);
}
}
void dp(int id) {
vector<int>& ring = bcc[id];
int sz = (int)ring.size();
vector<int> w(sz, 0), pre(sz, 0), suf(sz, 0);
for (int i = 0; i + 1 < sz; i++) {
w[i] = ew[ring[i]][ring[i + 1]];
}
w[sz - 1] = ew[ring[0]][ring[sz - 1]];
pre[0] = w[0]; suf[sz - 1] = w[sz - 1];
for (int i = 1; i < sz; i++) {
pre[i] = mul(pre[i - 1], w[i]);
}
for (int i = sz - 2; i >= 0; i--) {
suf[i] = mul(suf[i + 1], w[i]);
}
int p = ans[ring[0]];
for (int i = 1; i < sz; i++) {
int u = ring[i];
ans[u] = mul(sub(1, pre[i - 1]), sub(1, suf[i]));
ans[u] = mul(p, sub(1, ans[u]));
}
}
void dfs(int u, int f) {
// dbg(u, f);
if (u > n) dp(u - n);
for (int v: edge[u]) {
if (v == f) continue;
if (u <= n && v <= n) {
ans[v] = mul(ans[u], ew[u][v]);
}
dfs(v, u);
}
}
int main() {
int T, kase = 0; scanf("%d", &T);
while (T--) {
scanf("%d%d", &n, &m);
cactus::clear(n);
for (int i = 1; i <= n; i++) ew[i].clear();
for (int i = 1; i <= 2 * n; i++) edge[i].clear();
for (int i = 1, u, v, a, b; i <= m; i++) {
scanf("%d%d%d%d", &u, &v, &a, &b);
int w = mul(a, inv(b));
cactus::adde(u, v);
cactus::adde(v, u);
ew[u][v] = w;
ew[v][u] = w;
}
cactus::build();
ans[1] = 1;
dfs(1, 0);
int res = 0;
for (int i = 1; i <= n; i++) res = add(res, ans[i]);
printf("Case #%d: %d\n", ++kase, res);
}
return 0;
}
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