#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <stack>
#include <array>
#include <list>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
const ll MOD=1e9+7;
struct SCC{
    vector<vector<int>> g, gr;
    int n, k;
    vector<int> cmp, vs;
    vector<bool> used;
    void dfs(int x){
        used[x]=1;
        for(auto y:g[x]){
            if(!used[y]) dfs(y);
        }
        vs.push_back(x);
    }
    void rdfs(int v, int k){
        used[v]=1;
        cmp[v]=k;
        for(auto y:gr[v]){
            if(!used[y]) rdfs(y, k);
        }
    }
    SCC(const vector<vector<int>> &g):g(g), n(g.size()), cmp(n), used(n){
        gr.resize(n);
        for(int x=0; x<n; x++) for(auto y:g[x]) gr[y].push_back(x);
        for(int i=0; i<n; i++){
            if(!used[i]) dfs(i);
        }
        fill(used.begin(), used.end(), 0);
        k=0;
        for(int i=vs.size()-1; i>=0; i--){
            if(!used[vs[i]]) rdfs(vs[i], k++);
        }
    }
};
int u[200010], v[200010];
ll l[200020], a[200020];
vector<P> g[200020];
int main()
{
    int n, m;
    cin>>n>>m;
    vector<vector<int>> g0(n+1);
    for(int i=0; i<m; i++){
        cin>>u[i]>>v[i]>>l[i]>>a[i];
        g[u[i]].push_back({v[i], i});
        g0[u[i]].push_back(v[i]);
    }
    SCC scc(g0);
    vector<vector<int>> w(scc.k);
    for(int i=0; i<=n; i++){
        w[scc.cmp[i]].push_back(i);
    }
    bool dame[100010]={};
    for(int i=0; i<scc.k; i++){
        if(w[i].size()>1){
            for(auto x:w[i]) dame[x]=1;
        }
    }
    bool used[100010]={};
    used[0]=1;
    queue<int> que;
    que.push(0);
    while(!que.empty()){
        int x=que.front(); que.pop();
        for(auto q:g[x]){
            int y=q.first;
            if(!used[y]){
                que.push(y);
                used[y]=1;
            }
        }
    }
    if(!used[n]){
        cout<<0<<endl;
        return 0;
    }
    if(dame[0] || dame[n]){
        cout<<"INF"<<endl;
        return 0;
    }
    ll dp[100010]={};
    dp[0]=1;
    ll dps[100010]={};
    bool ok[100010]={}; ok[0]=1;
    for(int i=0; i<scc.k; i++){
        if(w[i].size()>1) continue;
        int x=w[i][0];
        for(auto q:g[x]){
            int i=q.second;
            int y=q.first;
            if(dame[y]){
                continue;
            }
            ok[y]=1;
            (dp[y]+=dp[x]*a[i])%=MOD;
            (dps[y]+=dps[x]*a[i]+dp[x]*l[i]%MOD*a[i])%=MOD;
        }
    }

    if(!ok[n]){
        cout<<"INF"<<endl;
    }else{
        cout<<dps[n]<<endl;
    }
    return 0;
}