using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Threading;
using System.Text;
using System.Text.RegularExpressions;
using System.Diagnostics;
using static util;
using P = pair<int, int>;

class Program {
    static void Main(string[] args) {
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        var solver = new Solver(sw);
        // var t = new Thread(solver.solve, 1 << 28); // 256 MB
        // t.Start();
        // t.Join();
        solver.solve();
        sw.Flush();
    }
}

class Solver {
    StreamWriter sw;
    Scan sc;
    void Prt(string a) => sw.WriteLine(a);
    void Prt<T>(IEnumerable<T> a) => Prt(string.Join(" ", a));
    void Prt(params object[] a) => Prt(string.Join(" ", a));
    public Solver(StreamWriter sw) {
        this.sw = sw;
        this.sc = new Scan();
    }

    public void solve() {
        int n, m;
        sc.Multi(out n, out m);
        ++n;
        var ed = new List<int>[n];
        var edg = new List<pair<pair<long, long>, int>>[n];
        for (int i = 0; i < n; i++)
        {
            ed[i] = new List<int>();
            edg[i] = new List<pair<pair<long, long>, int>>();
        }
        for (int i = 0; i < m; i++)
        {
            int u, v, l, a;
            sc.Multi(out u, out v, out l, out a);
            ed[u].Add(v);
            edg[u].Add(new pair<pair<long, long>, int>(new pair<long, long>(l, a), v));
        }
        var cmp = Scc.scc(ed, out _);
        int N = cmp.Max() + 1;
        var edge = new List<pair<pair<long, long>, int>>[N];
        for (int i = 0; i < N; i++)
        {
            edge[i] = new List<pair<pair<long, long>, int>>();
        }
        var self = new bool[N];
        for (int i = 0; i < n; i++)
        {
            foreach (var ((l, a), v) in edg[i])
            {
                if (cmp[i] != cmp[v]) {
                    edge[cmp[i]].Add(new pair<pair<long, long>, int>(new pair<long, long>(l, a), cmp[v]));
                }
                else {
                    self[cmp[i]] = true;
                }
            }
        }
        var dp = new pair<long, long>[N];
        var vis = new bool[N];
        for (int i = 0; i < N; i++)
        {
            dp[i] = new pair<long, long>(0, 0);
        }
        dp[cmp[0]] = new pair<long, long>(0, 1);
        vis[cmp[0]] = true;
        for (int i = 0; i < N; i++)
        {
            if (!vis[i]) continue;
            if (self[i]) dp[i].v1 = -1;
            foreach (var ((l, a), v) in edge[i])
            {
                if (dp[v].v1 == -1) continue;
                if (dp[i].v1 == -1) {
                    dp[v].v1 = -1;
                    continue;
                }
                dp[v].v1 = (dp[v].v1 + dp[i].v1 * a + dp[i].v2 * a % M * l) % M;
                dp[v].v2 = (dp[v].v2 + dp[i].v2 * a) % M;
            }
        }
        long ans = dp[cmp[n - 1]].v1;
        if (ans == -1) {
            Prt("INF");
        }
        else {
            Prt(ans);
        }

    }
}

class pair<T, U> : IComparable<pair<T, U>> {
    public T v1;
    public U v2;
    public pair() : this(default(T), default(U)) {}
    public pair(T v1, U v2) { this.v1 = v1; this.v2 = v2; }
    public int CompareTo(pair<T, U> a) {
        int c = Comparer<T>.Default.Compare(v1, a.v1);
        return c != 0 ? c : Comparer<U>.Default.Compare(v2, a.v2);
    }
    public override string ToString() => v1 + " " + v2;
    public void Deconstruct(out T a, out U b) { a = v1; b = v2; }
}
static class util {
    public static readonly int M = 1000000007;
    // public static readonly int M = 998244353;
    public static readonly long LM = 1L << 60;
    public static readonly double eps = 1e-11;
    public static void DBG(string a) => Console.Error.WriteLine(a);
    public static void DBG<T>(IEnumerable<T> a) => DBG(string.Join(" ", a));
    public static void DBG(params object[] a) => DBG(string.Join(" ", a));
    public static void Assert(params bool[] conds) {
        if (conds.Any(x => !x)) throw new Exception();
    }
    public static pair<T, U> make_pair<T, U>(T v1, U v2) => new pair<T, U>(v1, v2);
    public static int CompareList<T>(IList<T> a, IList<T> b) where T : IComparable<T> {
        for (int i = 0; i < a.Count && i < b.Count; i++)
            if (a[i].CompareTo(b[i]) != 0) return a[i].CompareTo(b[i]);
        return a.Count.CompareTo(b.Count);
    }
    public static bool inside(int i, int j, int h, int w) => i >= 0 && i < h && j >= 0 && j < w;
    public static readonly int[] dd = { 0, 1, 0, -1 };
    // static readonly string dstring = "RDLU";
    public static IEnumerable<P> adjacents(int i, int j) {
        for (int k = 0; k < 4; k++) yield return new P(i + dd[k], j + dd[k ^ 1]);
    }
    public static IEnumerable<P> adjacents(int i, int j, int h, int w)
        => adjacents(i, j).Where(p => inside(p.v1, p.v2, h, w));
    public static IEnumerable<P> adjacents(this P p) => adjacents(p.v1, p.v2);
    public static IEnumerable<P> adjacents(this P p, int h, int w) => adjacents(p.v1, p.v2, h, w);
    public static IEnumerable<int> all_subset(this int p) {
        for (int i = 0; ; i = i - p & p) {
            yield return i;
            if (i == p) break;
        }
    }
    public static Dictionary<T, int> compress<T>(this IEnumerable<T> a)
        => a.Distinct().OrderBy(v => v).Select((v, i) => new { v, i }).ToDictionary(p => p.v, p => p.i);
    public static Dictionary<T, int> compress<T>(params IEnumerable<T>[] a) => compress(a.SelectMany(x => x));
    public static T[] inv<T>(this Dictionary<T, int> dic) {
        var res = new T[dic.Count];
        foreach (var item in dic) res[item.Value] = item.Key;
        return res;
    }
    public static void swap<T>(ref T a, ref T b) where T : struct { var t = a; a = b; b = t; }
    public static void swap<T>(this IList<T> a, int i, int j) where T : struct { var t = a[i]; a[i] = a[j]; a[j] = t; }
    public static T[] copy<T>(this IList<T> a) {
        var ret = new T[a.Count];
        for (int i = 0; i < a.Count; i++) ret[i] = a[i];
        return ret;
    }
}

class Scan {
    StreamReader sr;
    public Scan() { sr = new StreamReader(Console.OpenStandardInput()); }
    public Scan(string path) { sr = new StreamReader(path); }
    public int Int => int.Parse(Str);
    public long Long => long.Parse(Str);
    public double Double => double.Parse(Str);
    public string Str => ReadLine.Trim();
    public string ReadLine => sr.ReadLine();
    public pair<T, U> Pair<T, U>() {
        T a; U b;
        Multi(out a, out b);
        return new pair<T, U>(a, b);
    }
    public P P => Pair<int, int>();
    public int[] IntArr => StrArr.Select(int.Parse).ToArray();
    public long[] LongArr => StrArr.Select(long.Parse).ToArray();
    public double[] DoubleArr => StrArr.Select(double.Parse).ToArray();
    public string[] StrArr => Str.Split(new[]{' '}, StringSplitOptions.RemoveEmptyEntries);
    bool eq<T, U>() => typeof(T).Equals(typeof(U));
    T ct<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
    T cv<T>(string s) => eq<T, int>()    ? ct<T, int>(int.Parse(s))
                       : eq<T, long>()   ? ct<T, long>(long.Parse(s))
                       : eq<T, double>() ? ct<T, double>(double.Parse(s))
                       : eq<T, char>()   ? ct<T, char>(s[0])
                                         : ct<T, string>(s);
    public void Multi<T>(out T a) => a = cv<T>(Str);
    public void Multi<T, U>(out T a, out U b) {
        var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]);
    }
    public void Multi<T, U, V>(out T a, out U b, out V c) {
        var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]);
    }
    public void Multi<T, U, V, W>(out T a, out U b, out V c, out W d) {
        var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]);
    }
    public void Multi<T, U, V, W, X>(out T a, out U b, out V c, out W d, out X e) {
        var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); e = cv<X>(ar[4]);
    }
    public void Multi<T, U, V, W, X, Y>(out T a, out U b, out V c, out W d, out X e, out Y f) {
        var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); e = cv<X>(ar[4]); f = cv<Y>(ar[5]);
    }
}

static class Scc {
    public static int[] scc(List<int>[] edge, out List<int>[] cmped_edge) {
        int n = edge.Length;
        var vis = new bool[n];
        var st = new Stack<int>();
        var cmp = new int[n];
        for (int i = 0; i < n; i++) if (!vis[i]) dfs(i, -1, vis, st, cmp, edge);

        vis = new bool[n];
        var rev = new List<int>[n];
        for (int i = 0; i < n; i++) rev[i] = new List<int>();
        for (int i = 0; i < n; i++) foreach (int j in edge[i]) rev[j].Add(i);
        int k = 0;
        while (st.Any()) {
            int i = st.Pop();
            if (!vis[i]) dfs(i, k++, vis, new Stack<int>(), cmp, rev);
        }
        var cmped_edge_set = new HashSet<int>[k];
        for (int i = 0; i < k; i++) cmped_edge_set[i] = new HashSet<int>();
        for (int i = 0; i < n; i++)
            foreach (var item in edge[i])
                if (cmp[i] != cmp[item])
                    cmped_edge_set[cmp[i]].Add(cmp[item]);

        cmped_edge = new List<int>[k];
        for (int i = 0; i < k; i++) cmped_edge[i] = cmped_edge_set[i].ToList();

        return cmp;
    }
    static void dfs(int v, int k, bool[] vis, Stack<int> st, int[] cmp, List<int>[] edge) {
        vis[v] = true;
        cmp[v] = k;
        foreach (int i in edge[v]) if (!vis[i]) dfs(i, k, vis, st, cmp, edge);
        st.Push(v);
    }
}