#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define each(e, v) for(auto &e: v)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const int MOD = 1000000007;
//const int MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};

struct io_setup{
    io_setup(){
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout << fixed << setprecision(15);
    }
} io_setup;

template<int mod>
struct Mod_Int{
    int x;

    Mod_Int() : x(0) {}

    Mod_Int(ll y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    Mod_Int &operator += (const Mod_Int &p){
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }

    Mod_Int &operator -= (const Mod_Int &p){
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }

    Mod_Int &operator *= (const Mod_Int &p){
        x = (int) (1LL * x * p.x % mod);
        return *this;
    }

    Mod_Int &operator /= (const Mod_Int &p){
        *this *= p.inverse();
        return *this;
    }

    Mod_Int &operator ++ () {return *this += Mod_Int(1);}

    Mod_Int operator ++ (int){
        Mod_Int tmp = *this;
        ++*this;
        return tmp;
    }

    Mod_Int &operator -- () {return *this -= Mod_Int(1);}

    Mod_Int operator -- (int){
        Mod_Int tmp = *this;
        --*this;
        return tmp;
    }

    Mod_Int operator - () const {return Mod_Int(-x);}

    Mod_Int operator + (const Mod_Int &p) const {return Mod_Int(*this) += p;}

    Mod_Int operator - (const Mod_Int &p) const {return Mod_Int(*this) -= p;}

    Mod_Int operator * (const Mod_Int &p) const {return Mod_Int(*this) *= p;}

    Mod_Int operator / (const Mod_Int &p) const {return Mod_Int(*this) /= p;}

    bool operator == (const Mod_Int &p) const {return x == p.x;}

    bool operator != (const Mod_Int &p) const {return x != p.x;}

    Mod_Int inverse() const {
        assert(*this != Mod_Int(0));
        return pow(mod-2);
    }

    Mod_Int pow(ll k) const{
        Mod_Int now = *this, ret = 1;
        for(; k; k >>= 1, now *= now){
            if(k&1) ret *= now;
        }
        return ret;
    }

    friend ostream &operator << (ostream &os, const Mod_Int &p){
        return os << p.x;
    }

    friend istream &operator >> (istream &is, Mod_Int &p){
        ll a;
        is >> a;
        p = Mod_Int<mod>(a);
        return is;
    }
};

using mint = Mod_Int<MOD>;

struct Graph{
    struct edge{
        int to; mint l, a;
        edge(int to, mint l, mint a) : to(to), l(l), a(a) {}
    };

    vector<vector<edge>> es, rs;
    vector<bool> tw, c1, c2;
    vector<mint> dp1, dp2;
    const int n;

    Graph(int n) : n(n){
        es.resize(n), rs.resize(n);
        tw.assign(n, false), c1.assign(n, false), c2.assign(n, false);
        dp1.assign(n, 0), dp2.assign(n, 0);
    }

    void add_edge(int from, int to, mint l, mint a, bool directed = true){
        es[from].eb(to, l, a), rs[to].eb(from, l, a);
    }

    void dfs(int now){
        c1[now] = true;
        each(e, es[now]){
            if(!c1[e.to]) dfs(e.to);
        }
    }

    void rfs(int now){
        c2[now] = true;
        each(e, rs[now]){
            if(!c2[e.to]) rfs(e.to);
        }
    }

    void solve(int s, int t){
        dfs(s), rfs(t);
        rep(i, n){
            if(tw[i] && c1[i] && c2[i]){
                cout << "INF\n";
                return;
            }
        }
        dp1[s] = 0, dp2[s] = 1;
        rep(i, n){
            each(e, es[i]){
                dp1[e.to] += dp1[i]*e.a+dp2[i]*e.a*e.l;
                dp2[e.to] += dp2[i]*e.a;
            }
        }

        cout << dp1[t] << '\n';
    }
};

struct Strongly_Connected_Components{
    vector<vector<int>> es, rs;
    vector<int> vs, comp;
    vector<bool> used;
    const int n;

    Strongly_Connected_Components(int n) : n(n){
        es.resize(n), rs.resize(n);
        vs.resize(n), comp.resize(n), used.resize(n);
    }

    void add_edge(int from, int to, bool directed = false){
        es[from].pb(to), rs[to].pb(from);
        if(!directed) es[to].pb(from), rs[from].pb(to);
    }

    void topological_sort(int now){
        used[now] = true;
        each(e, es[now]) if(!used[e]) topological_sort(e);
        vs.pb(now);
    }

    void track_back(int now, int cnt){
        used[now] = true, comp[now] = cnt;
        each(e, rs[now]) if(!used[e]) track_back(e, cnt);
    }

    Graph decompose(){
        fill(all(used), false);
        rep(i, n) if(!used[i]) topological_sort(i);
        fill(all(used), false), reverse(all(vs));
        int cnt = 0;
        each(e, vs) if(!used[e]) track_back(e, cnt++);
        Graph G(cnt);
        vector<int> K(cnt, 0);
        rep(i, n) K[comp[i]]++;
        rep(i, cnt){
            if(K[i] > 1) G.tw[i] = true;
        }
        /*
        rep(i, n){
            each(e, es[i]){
                int u = comp[i], v = comp[e];
                if(u != v) G.add_edge(u, v, true);
            }
        }
        */
        return G;
    }

    int operator [] (int k) const {return comp[k];}
};

int main(){
    int N, M;
    cin >> N >> M;

    vector<int> u(M), v(M);
    vector<mint> l(M), a(M);
    Strongly_Connected_Components scc(N+1);

    rep(i, M){
        cin >> u[i] >> v[i] >> l[i] >> a[i];
        scc.add_edge(u[i], v[i], true);
    }

    Graph G = scc.decompose();
    
    rep(i, M){
        int U = scc[u[i]], V = scc[v[i]];
        if(U != V) G.add_edge(U, V, l[i], a[i], true);
    }

    int s = scc[0], t = scc[N];
    G.solve(s, t);
}