#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y));
#define chmax(x,y) x = max((x),(y));
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;

template<int mod> struct ModInt{
    long long x=0; 
    constexpr ModInt(long long x=0):x((x%mod+mod)%mod){}
    constexpr ModInt operator+(const ModInt& r)const{return ModInt(*this)+=r;}
    constexpr ModInt operator-(const ModInt& r)const{return ModInt(*this)-=r;}
    constexpr ModInt operator*(const ModInt& r)const{return ModInt(*this)*=r;}
    constexpr ModInt operator/(const ModInt& r)const{return ModInt(*this)/=r;}
    constexpr ModInt& operator+=(const ModInt& r){ if((x+=r.x)>=mod) x-=mod; return *this;}
    constexpr ModInt& operator-=(const ModInt& r){ if((x-=r.x)<0) x+=mod; return *this;}
    constexpr ModInt& operator*=(const ModInt& r){ if((x*=r.x)>=mod) x%=mod; return *this;}
    constexpr ModInt& operator/=(const ModInt& r){ return *this*=r.inv();}
    ModInt inv() const {
        long long s=x,sx=1,sy=0,t=mod,tx=0,ty=1;
        while(s%t!=0){
            long long temp=s/t,u=s-t*temp,ux=sx-temp*tx,uy=sy-temp*ty;
            s=t;sx=tx;sy=ty;
            t=u;tx=ux;ty=uy;
        }
        return ModInt(tx);
    }
    ModInt pow(long long n) const {
        ModInt a=1;
        ModInt b=*this;
        while(n>0){
            if(n&1) a*=b;
            b*=b;
            n>>=1;
        }
        return a;
    }
    friend constexpr ostream& operator<<(ostream& os,const ModInt<mod>& a) {return os << a.x;}
    friend constexpr istream& operator>>(istream& is,ModInt<mod>& a) {return is >> a.x;}
};
using mint = ModInt<MOD>;

vector<int> ToplogicalSort(vector<vector<int>> &G,vector<int> &Indegree){
    int n = (int)G.size();
    vector<int> res(n);
    queue<int> q;
    for(int i=0;i<n;i++){
        if(Indegree[i] == 0){
            q.push(i);
        }
    }
    int i = 0;
    while(!q.empty()){
        int now = q.front();
        res[i++] = now;
        q.pop();
        for(int v:G[now]){
            --Indegree[v];
            if(Indegree[v] == 0) q.push(v);
        }
    }
    if(i==n) return res;
    else return {-1};
}

struct edge{
    ll to;
    ll l,a;
};

mint dp[100005];
mint cnt[100005];

int main(){
    int n,m;
    cin >> n >> m;
    vector<vector<int>> G(n+1);
    vector<vector<edge>> graph(n+1);
    vector<int> Indegree(n+1,0);
    rep(i,m){
        ll u,v,l,a;
        cin >> u >> v >> l >> a;
        G[u].push_back(v);
        graph[u].push_back(edge{v,l,a});
        Indegree[v]++;
    }
    vector<int> topo = ToplogicalSort(G,Indegree);
    if(topo[0]==-1){
        cout << "INF" << endl;
        return 0;
    }
    dp[0] = 0;
    cnt[0] = 1;
    for(int i:topo){
        for(auto e:graph[i]){
            dp[e.to] += dp[i] + cnt[i] * e.a * e.l;
            cnt[e.to] += cnt[i] * e.a;
        }
    }
    cout << dp[n] << endl;
    return 0;
}