using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
using System.Threading;
using System.Runtime.CompilerServices;
static class Program{
	const int mod=(int)1e9+7;
	const long inf=long.MaxValue-1;
	static List<ValueTuple<int,int,int>>[] li;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.Ia;
		int n=s[0]+1,m=s[1];
		li=new List<ValueTuple<int,int,int>>[n+1];
		for(int i=1;i<=n;i++){li[i]=new List<ValueTuple<int,int,int>>();}
		for(int i=0;i<m;i++){
			var e=sc.Ia;
			li[e[0]+1].Add(ValueTuple.Create(e[1]+1,e[2],e[3]));
		}
		var Tp=new Tp(li);
		if(Tp.ba[n]){
			var qu=new Queue<ValueTuple<int,int>>();
			qu.Enqueue(ValueTuple.Create(1,0));
			var b=new bool[n+1];
			while(qu.Count>0){
				var e=qu.Dequeue();
				if(b[e.Item1]){continue;}
				b[e.Item1]=true;
				for(int j = 0;j<li[e.Item1].Count;j++) {
					if(!b[li[e.Item1][j].Item1]){qu.Enqueue(ValueTuple.Create(li[e.Item1][j].Item1,e.Item2+1));}
				}
			}
			Console.WriteLine(b[n]?"INF":"0");
			return;
		}
		var dp1=new Mint[n+1];
		var dp2=new Mint[n+1];
		dp2[1]=1;
		for(int i = 0;i < n;i++) {
			for(int j = 0;j < li[Tp.a2[i]].Count;j++) {
				dp1[li[Tp.a2[i]][j].Item1]+=dp2[Tp.a2[i]]*li[Tp.a2[i]][j].Item3*li[Tp.a2[i]][j].Item2+dp1[Tp.a2[i]]*li[Tp.a2[i]][j].Item3;
				dp2[li[Tp.a2[i]][j].Item1]+=dp2[Tp.a2[i]]*li[Tp.a2[i]][j].Item3;
			}
		}
		Console.WriteLine(dp1[n]);
	}
}
public class Tp{
	public int[] a1,a2;
	public bool[] ba;
	public bool bo=false;
	public Tp(List<(int,int,int)>[] li){
		int n=li.Length;
		var b=new int[n];
		a1=new int[n];
		a2=new int[n-1];
		ba=new bool[n];
		var k=n-1;
		var thread=new Thread(new ThreadStart(()=>{
			for(int i=n-1;i>0;i--) {if(b[i]==0){Fu(i);}}
			void Fu(int a) {
				b[a]=2;
				for(int i=0;i<li[a].Count;i++){
					if(b[li[a][i].Item1]==0){Fu(li[a][i].Item1);}
					else if(b[li[a][i].Item1]==2){ba[a]=ba[li[a][i].Item1]=bo=true;}
				}
				a1[a]=k;
				a2[--k]=a;
				b[a]=1;
			}
		}),1<<27);
		thread.Start();
		thread.Join();
		for(int i=0;i<a2.Length;i++) {
			for(int j = 0;j<li[a2[i]].Count;j++) {ba[li[a2[i]][j].Item1]|=ba[a2[i]];}
		}
	}
}
public struct Mint{
	const int mod=(int)1e9+7;
	private long d;
	public Mint(long d){this.d=d;}
	public static implicit operator Mint(long d){return new Mint(d%mod);}
	public static explicit operator long(Mint d){return d.d;}
	public override string ToString(){return d.ToString();}
	public static Mint operator+(Mint a,long b){a.d=(a.d+b)%mod;return a;}
	public static Mint operator+(Mint a,Mint b){a.d=(a.d+b.d)%mod;return a;}
	public static Mint operator-(Mint a,long b){a.d=(mod+a.d-b)%mod;return a;}
	public static Mint operator-(Mint a,Mint b){a.d=(mod+a.d-b.d)%mod;return a;}
	public static Mint operator*(Mint a,long b){a.d=(a.d*b)%mod;return a;}
	public static Mint operator*(Mint a,Mint b){a.d=(a.d*b.d)%mod;return a;}
	public static Mint operator/(Mint a,long b){a.d=(a.d*Mi(b))%mod;return a;}
	public static Mint operator/(Mint a,Mint b){a.d=(a.d*Mi(b.d))%mod;return a;}
	public static bool operator==(Mint a,long b){return (long)a==b;}
	public static bool operator!=(Mint a,long b){return (long)a!=b;}
	public override bool Equals(object obj){return false;}
	public override int GetHashCode(){return 0;}
	public static long Mi(long a){
		a=(a+mod)%mod;
		long b=mod,u=1,v=0;
		while(b>0){
			long t=a/b;
			a-=t*b;(a,b)=(b,a);
			u-=t*v;(u,v)=(v,u);
		}
		u%=mod;
		if(u<0){u+=mod;}
		return u%mod;
	}
}
public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}
public class Sct{
	private StreamReader sr;
	public Sct(string t){sr=new StreamReader(t);}
	public int I{get{return int.Parse(sr.ReadLine());}}
	public long L{get{return long.Parse(sr.ReadLine());}}
	public double D{get{return double.Parse(sr.ReadLine());}}
	public string S{get{return sr.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(sr.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(sr.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(sr.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return sr.ReadLine().Split();}}
	public object[] Oa{get{return sr.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+sr.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+sr.ReadLine()+b).Split(),int.Parse);}
	public int[] Ia3(int a){return Array.ConvertAll((sr.ReadLine()+" "+a.ToString()).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+sr.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+sr.ReadLine()+b).Split(),long.Parse);}
	public long[] La3(int a){return Array.ConvertAll((sr.ReadLine()+" "+a.ToString()).Split(),long.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(sr.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,sr.ReadLine().Split());}return a;}
}