#include<iostream>
#include<array>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<tuple>
#include<cassert>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define Per(i,sta,n) for(int i=n-1;i>=sta;i--)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;
int dx[4]={1,-1,0,0};
int dy[4]={0,0,1,-1};
template<class T>bool chmax(T &a, const T &b) {if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a, const T &b) {if(b<a){a=b;return 1;}return 0;}

template<int mod>
struct ModInt {
    long long x;
    static constexpr int MOD = mod;
 
    ModInt() : x(0) {}
    ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    explicit operator int() const {return x;}
 
    ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }
    ModInt &operator-=(const ModInt &p) {
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }
    ModInt &operator*=(const ModInt &p) {
        x = (int)(1LL * x * p.x % mod);
        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; }
    ModInt operator%(const ModInt &p) const { return ModInt(0); }         
 
    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 = mod, 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 power(long long n) const {
        ModInt ret(1), mul(x);
        while(n > 0) {
            if(n & 1)
            ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }

    ModInt power(const ModInt p) const{
        return ((ModInt)x).power(p.x);
    }

    friend ostream &operator<<(ostream &os, const ModInt<mod> &p) {
        return os << p.x;
    }
    friend istream &operator>>(istream &is, ModInt<mod> &a) {
        long long x;
        is >> x;
        a = ModInt<mod>(x);
        return (is);
    }
};

using modint = ModInt<mod>;



int n,m;
struct edge{
  int to,l,a;
  edge(){}
  edge(int to,int l,int a):to(to),l(l),a(a){}
};

bool visited[100010],finish[100010],roop=false;
modint dp1[100010],dp2[100010];
vector<vector<edge>> G,rG;
vector<bool> R1,R2;

void dfs1(int s,vector<vector<edge>> &G,vector<bool> &R){
  R[s]=true;
  for(edge e:G[s]){
    if(R[e.to]) continue;
    dfs1(e.to,G,R);
  }
}

// vector<int> topological_sort(int n,vector<vector<int>> &G){
//   vector<int> deg(n,0);
//   rep(i,n){
//     for(int t:G[i]){

//     }
//   }
// }


void calc(int s){
  visited[s]=true;
  for(edge e:rG[s]){
    if(!R1[e.to] || !R2[e.to]) continue;
    if(visited[e.to] && !finish[e.to]){
      roop=true;
      continue;
    }
    if(!visited[e.to]) calc(e.to);
    dp1[s]+=dp1[e.to]*e.a+dp2[e.to]*e.a*e.l;
    dp2[s]+=dp2[e.to]*e.a;
  }
  finish[s]=true;
}

void solve(){
  cin >> n >> m;
  G.resize(n+1,vector<edge>());rG.resize(n+1,vector<edge>());
  rep(i,m){
    int u,v,l,a;cin >> u >> v >> l >> a;
    G[u].push_back({v,l,a});
    rG[v].push_back({u,l,a});
  }
  R1.resize(n+1,false);R2.resize(n+1,false);
  dfs1(0,G,R1);dfs1(n,rG,R2);
  if(!R1[n]){
    cout << 0 << endl;
    return;
  }
  dp2[0]=1;
  calc(n);
  // rep(i,n+1){
  //   cout << i << " " << dp1[i] << " " << dp2[i] << endl;
  // }
  if(roop) {
    cout << "INF" << endl;
    return;
  }
  cout << dp1[n] << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(50);
    solve();
}