#include using namespace std; using ll = long long; using ld = long double; using VI = vector; using VL = vector; using VS = vector; template using PQ = priority_queue, greater>; #define FOR(i,a,n) for(int i=(a);i<(n);++i) #define eFOR(i,a,n) for(int i=(a);i<=(n);++i) #define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i) #define erFOR(i,a,n) for(int i=(n);i>=(a);--i) #define SORT(a) sort(a.begin(),a.end()) #define rSORT(a) sort(a.rbegin(),a.rend()) #define fSORT(a,f) sort(a.begin(),a.end(),f) #define all(a) a.begin(),a.end() #define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x)) #define tp(a,i) get(a) #ifdef _DEBUG #define line cout << "-----------------------------\n" #define stop system("pause") #define debug(x) print(x) #endif constexpr ll INF = 1000000000; constexpr ll LLINF = 1LL << 60; constexpr ll mod = 1000000007; constexpr ll MOD = 998244353; constexpr ld eps = 1e-10; constexpr ld pi = 3.1415926535897932; templateinline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; } templateinline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; } inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } templateinline istream& operator>>(istream& is, vector& v) { for (auto& a : v)is >> a; return is; } templateinline istream& operator>>(istream& is, pair& p) { is >> p.first >> p.second; return is; } templateinline vector vec(size_t a) { return vector(a); } templateinline vector defvec(T def, size_t a) { return vector(a, def); } templateinline auto vec(size_t a, Ts... ts) { return vector(ts...))>(a, vec(ts...)); } templateinline auto defvec(T def, size_t a, Ts... ts) { return vector(def, ts...))>(a, defvec(def, ts...)); } templateinline void print(const T& a) { cout << a << "\n"; } templateinline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); } templateinline void print(const vector& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); } templateinline void print(const vector>& v) { for (auto& a : v)print(a); } inline string reversed(const string& s) { string t = s; reverse(all(t)); return t; } templateinline T sum(const vector& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); } templateinline void END(T s) { print(s); exit(0); } void END() { exit(0); } template struct ModInt { int x; ModInt() : x(0) {} ModInt(ll y) : x(y >= 0 ? y % modulo : (modulo - (-y) % modulo) % modulo) {} ModInt& operator+=(const ModInt& p) { if ((x += p.x) >= modulo) x -= modulo; return *this; } ModInt& operator-=(const ModInt& p) { if ((x += modulo - p.x) >= modulo) x -= modulo; return *this; } ModInt& operator*=(const ModInt& p) { x = (int)(1LL * x * p.x % modulo); return *this; } ModInt& operator/=(const ModInt& p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt& p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt& p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt& p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt& p) const { return ModInt(*this) /= p; } bool operator==(const ModInt& p) const { return x == p.x; } bool operator!=(const ModInt& p) const { return x != p.x; } ModInt inverse() const { int a = x, b = modulo, u = 1, v = 0, t; while (b > 0) { t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } ModInt pow(ll e) { ll a = 1, p = x; while (e > 0) { if (e % 2 == 0) { p = (p * p) % modulo; e /= 2; } else { a = (a * p) % modulo; e--; } } return ModInt(a); } friend ostream& operator<<(ostream& os, const ModInt& p) { return os << p.x; } friend istream& operator>>(istream& is, ModInt& a) { ll x; is >> x; a = ModInt(x); return (is); } }; using modint = ModInt; int main() { init(); int n, m; cin >> n >> m; vector>> g(n + 1), r(n + 1); FOR(i, 0, m) { int u, v, l, a; cin >> u >> v >> l >> a; g[u].emplace_back(v, l, a); r[v].emplace_back(u, l, a); } vector used(n + 1); stack st; auto dfs1 = [&](auto&& f, int cur)->void { used[cur] = true; for (auto [to, l, a] : g[cur]) { if (used[to])continue; f(f, to); } st.push(cur); }; FOR(i, 0, n + 1)if (!used[i])dfs1(dfs1, i); int cnt; VI loop(n + 1); auto dfs2 = [&](auto&& f, int cur)->bool { used[cur] = true; ++cnt; for (auto [to, l, a] : r[cur]) { if (used[to])continue; f(f, to); } if (cnt > 1) { loop[cur] = 1; return true; } return false; }; used.assign(n + 1, false); while (!st.empty()) { cnt = 0; dfs2(dfs2, st.top()); st.pop(); } used.assign(n + 1, false); queue bfs; bfs.push(0); while (!bfs.empty()) { int cur = bfs.front(); bfs.pop(); for (auto [to, l, a] : g[cur]) { if (used[to])continue; used[to] = true; bfs.push(to); } } FOR(i, 0, n)loop[i] += used[i]; used.assign(n + 1, false); bfs.push(n); while (!bfs.empty()) { int cur = bfs.front(); bfs.pop(); for (auto [to, l, a] : r[cur]) { if (used[to])continue; used[to] = true; bfs.push(to); } } FOR(i, 0, n)loop[i] += used[i]; VI in(n + 1); FOR(cur, 0, n + 1)for (auto [to, l, a] : g[cur])++in[to]; vector dp1(n + 1); dp1[0] = 1; FOR(i, 0, n + 1)if (in[i] == 0) { bfs.push(i); } while (!bfs.empty()) { int cur = bfs.front(); bfs.pop(); for (auto [to, l, a] : g[cur]) { dp1[to] += dp1[cur] * a; if (--in[to] == 0)bfs.push(to); } } in.assign(n + 1, 0); FOR(cur, 0, n + 1)for (auto [to, l, a] : r[cur])++in[to]; vector dp2(n + 1); dp2[n] = 1; FOR(i, 0, n + 1)if (in[i] == 0) { bfs.push(i); } while (!bfs.empty()) { int cur = bfs.front(); bfs.pop(); for (auto [to, l, a] : r[cur]) { dp2[to] += dp2[cur] * a; if (--in[to] == 0)bfs.push(to); } } if (*max_element(all(loop)) >= 3)END("INF"); modint ans = 0; FOR(i, 0, n + 1)for (auto [to, l, a] : g[i])ans += dp1[i] * dp2[to] * l * a; print(ans); return 0; }