use std::{collections::BinaryHeap, cmp::Reverse};

const MOD: usize = 1e9 as usize + 7;

fn topologycal_sort(paths: &Vec<Vec<usize>>) -> Vec<usize> {
    let n = paths.len();
    let mut ret = vec![];
    let mut ins = vec![0usize; n];
    for i in 0..n {
        for &v in paths[i].iter() {
            ins[v] += 1;
        }
    }
    let mut que = BinaryHeap::new();
    for i in 0..n {
        if ins[i] == 0 {
            que.push(Reverse(i));
        }
    }
    while let Some(Reverse(x)) = que.pop() {
        ret.push(x);
        for &v in paths[x].iter() {
            ins[v] -= 1;
            if ins[v] == 0 {
                que.push(Reverse(v));
            }
        }
    }
    ret
}

fn main() {
    let mut nm = String::new();
    std::io::stdin().read_line(&mut nm).ok();
    let nm: Vec<usize> = nm.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nm[0];
    let m = nm[1];
    let mut paths_for_dag = vec![vec![]; n+1];
    let mut paths = vec![vec![]; n+1];
    for _ in 0..m {
        let mut temp = String::new();
        std::io::stdin().read_line(&mut temp).ok();
        let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let u = temp[0];
        let v = temp[1];
        let l = temp[2];
        let a = temp[3];
        paths_for_dag[u].push(v);
        paths[u].push((v, l, a));
    }

    let temp = topologycal_sort(&paths_for_dag);
    if temp.len() < n+1 {
        println!("INF");
        return;
    }
    let mut cnts = vec![0usize; n+1];
    for &u in temp.iter() {
        for &(v, l, a) in paths[u].iter() {
            cnts[v] += l * a + cnts[u];
            cnts[v] %= MOD;
        }
    }
    println!("{}", cnts[n]);
}