#include <iostream>
#include <vector>
#include <algorithm>
#include <array>
#include <iterator>
#include <string>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <bitset>
#include <random>
#include <utility>
#include <functional>
using namespace std;
template<int m> struct modint
{
	private:
	unsigned int value;
	static constexpr int mod() {return m;}

	public:
	constexpr modint(const long long x = 0) noexcept
	{
		long long y = x;
		if(y < 0 || y >= mod())
		{
			y %= mod();
			if(y < 0) y += mod();
		}
		value = (unsigned int)y;
	}
	static constexpr int get_mod() noexcept {return m;}
	static constexpr int primitive_root() noexcept
	{
		assert(m == 998244353);
		return 3;
	}
	constexpr unsigned int val() noexcept {return value;}
	constexpr modint &operator+=(const modint &other) noexcept
	{
		value += other.value;
		if(value >= mod()) value -= mod();
		return *this;
	}
	constexpr modint &operator-=(const modint &other) noexcept
	{
		unsigned int x = value;
		if(x < other.value) x += mod();
		x -= other.value;
		value = x;
		return *this;
	}
	constexpr modint &operator*=(const modint &other) noexcept
	{
		unsigned long long x = value;
		x *= other.value;
		value = (unsigned int) (x % mod());
		return *this;
	}
	constexpr modint &operator/=(const modint &other) noexcept
	{
		return *this *= other.inverse();
	}
	constexpr modint inverse() const noexcept
	{
		assert(value);
		long long a = value,b = mod(),x = 1,y = 0;
		while(b)
		{
			long long q = a/b;
			a -= q*b; swap(a,b);
			x -= q*y; swap(x,y);
		}
		return modint(x);
	}
	constexpr modint power(long long N) const noexcept
	{
		assert(N >= 0);
		modint p = *this,ret = 1;
		while(N)
		{
			if(N & 1) ret *= p;
			p *= p;
			N >>= 1;
		}
		return ret;
	}
	constexpr modint operator+() {return *this;}
	constexpr modint operator-() {return modint() - *this;}
	constexpr modint &operator++(int) noexcept {return *this += 1;}
	constexpr modint &operator--(int) noexcept {return *this -= 1;}
	friend modint operator+(const modint& lhs, const modint& rhs) {return modint(lhs) += rhs;}
	friend modint operator-(const modint& lhs, const modint& rhs) {return modint(lhs) -= rhs;}
	friend modint operator*(const modint& lhs, const modint& rhs) {return modint(lhs) *= rhs;}
	friend modint operator/(const modint& lhs, const modint& rhs) {return modint(lhs) /= rhs;}
	friend ostream &operator<<(ostream &os,const modint &x) {return os << x.value;}
};
/* using mint = modint<998244353>; */
using mint = modint<1000000007>;
void Main()
{
	int N,M;
	cin >> N >> M;
	vector<vector<tuple<int,int,int>>> G(N + 1);
	vector<vector<int>> RG(N + 1);
	for(int i = 0;i < M;i++)
	{
		int u,v,l,a;
		cin >> u >> v >> l >> a;
		G[v].push_back(make_tuple(u,l,a));
		RG[u].push_back(v);
	}
	vector<int> vis(N + 1),rvis(N + 1);
	{
		auto dfs = [&](auto dfs,int u) -> void
		{
			vis[u] = 1;
			for(const auto &[v,l,a] : G[u])
			{
				if(vis[v]);
				else
				{
					dfs(dfs,v);
				}
			}
		};
		auto rdfs = [&](auto dfs,int u) -> void
		{
			rvis[u] = 1;
			for(int v : RG[u])
			{
				if(rvis[v]);
				else
				{
					dfs(dfs,v);
				}
			}
		};
		dfs(dfs,N);
		rdfs(rdfs,0);
	}
	vector<mint> dp(N + 1),way(N + 1);
	vector<int> seen(N + 1),fin(N + 1);
	bool inf = false;
	auto dfs = [&](auto dfs,int u) -> void
	{
		if(!vis[u] || !rvis[u])
		{
			return;
		}
		seen[u] = 1;
		if(u == 0)
		{
			dp[u] = 0;
			way[u] = 1;
		}
		for(const auto &[v,l,a] : G[u])
		{
			if(seen[v])
			{
				if(fin[v]);
				else
				{
					inf = true;
					return;
				}
			}
			else
			{
				dfs(dfs,v);
				if(inf)
				{
					return;
				}
			}
			dp[u] += (dp[v] + l * way[v]) * a;
			way[u] += way[v] * a;
		}
		fin[u] = 1;
		return;
	};
	dfs(dfs,N);
	if(inf)
	{
		cout << "INF\n";
	}
	else
	{
		cout << dp[N] << "\n";
	}
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	/* cin >> tt; */
	while(tt--) Main();
}