#include <bits/stdc++.h>
using namespace std;

using VS = vector<string>;    using LL = long long;
using VI = vector<int>;       using VVI = vector<VI>;
using PII = pair<int, int>;   using PLL = pair<LL, LL>;
using VL = vector<LL>;        using VVL = vector<VL>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))
#define FOR(i, s, e) for (int(i) = (s); (i) < (e); (i)++)
#define FORR(i, s, e) for (int(i) = (s); (i) > (e); (i)--)
#define debug(x) cerr << #x << ": " << x << endl
const int INF = 1e9;                          const LL LINF = 1e16;
const LL MOD = 1000000007;                    const double PI = acos(-1.0);
int DX[8] = { 0, 0, 1, -1, 1, 1, -1, -1 };    int DY[8] = { 1, -1, 0, 0, 1, -1, 1, -1 };

/* -----  2018/01/29  Problem: AOJ 0304 / Link: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=0304  ----- */
/* ------問題------



-----問題ここまで----- */
/* -----解説等-----

なんか制約条件がLPになるけど式に出てくる変数の数から最短経路になるアレ？

----解説ここまで---- */

/* ベルマンフォード 経路復元なし
負辺に対しても最短経路を求めることができる
頂点に着目した遷移を行う？
閉路検出は頂点の更新回数がV-1回を超えたときに閉路検出としてこれを出力する
O(VE) */

struct Edge {
	int to, cost;
	Edge(int t, int c = 0) : to(t), cost(c)
	{}
	bool operator>(const Edge& rhs) const {
		return cost > rhs.cost;
	}
	bool operator<(const Edge& rhs) const {
		return cost < rhs.cost;
	}

};
typedef vector< vector<Edge> > Graph;


//precondition: d.size == V
//O(V*E)
int BellmanFord(const Graph& G) {
	const int V = G.size();
	VI d(V, INF);
	d[0] = 0;
	FOR(i, 0, V) {
		FOR(j, 0, V) {
			FOR(k, 0, SZ(G[j])) {
				Edge e = G[j][k];
				if (d[e.to] > d[j] + e.cost) {
					d[e.to] = d[j] + e.cost;
					if (i == V - 1 || d[e.to] < 0)return -1;
				}
			}

		}
	}
	//FOR(i, 0, V) {
	//	cout<<d[i] <<" ";
	//}cout << endl;
	return *max_element(ALL(d));
}
LL N, C;

LL A[202], B[202], OP[202], PM[202], D[202];

LL ans = 0LL;
int numb(string &s, int &i) {
	int ret = 0;
	while (isdigit(s[i])) {
		ret *= 10;
		ret += s[i] - '0';
		i++;
	}
	return ret;
}
void parse(string &s, int &i) {
	int a, b, c, op1, op2;
	a = numb(s, i);
	static int cnt = 0;
	op1 = 0;
	if (s[i] == '*') { i++, op1 = 2; }
	else if (s[i] == '>') {
		i += 2;	op1 = 1;
	}
	else {
		i += 2;	op1 = 0;
	}

	b = numb(s, i);

	op2 = 0;
	if (s[i] == '+') {
		op2 = 1;
	}
	i++;
	c = numb(s, i);
	A[cnt] = a - 1; B[cnt] = b - 1; D[cnt] = c;
	OP[cnt] = op1; PM[cnt] = op2;
	cnt++;
}

int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	cin >> N >> C;
	VI IDs;
	FOR(i, 0, C) {
		string s;
		cin >> s;
		int idx = 0;
		parse(s, idx);
		if (OP[i] == 2)IDs.push_back(i);

	}
	ans = -1;
	FOR(i, 0, (1 << (SZ(IDs)))) {
		FOR(j, 0, SZ(IDs)) {
			OP[IDs[j]] = (i&(1 << j) ? 1 : 0);
		}
		Graph G(N);
		FOR(i, 0, C) {
			if (OP[i] == 0) {// <=
				G[B[i]].push_back(Edge(A[i], 0));
				if (PM[i] == 0) {// -
					G[A[i]].push_back(Edge(B[i], D[i]));
				}
				else {// +
					G[B[i]].push_back(Edge(A[i], -D[i]));
				}
			}
			else { // -
				G[A[i]].push_back(Edge(B[i], 0));
				if (PM[i] == 0) {
					G[B[i]].push_back(Edge(A[i], D[i]));
				}
				else {// +
					G[A[i]].push_back(Edge(B[i], -D[i]));
				}
			}

		}
		ans = max(ans, (LL)BellmanFord(G));
	}
	if (ans >= INF) {
		cout << "inf" << endl;
	}
	else
		cout << ans << "\n";

	return 0;
}



Measured memory_bytes: 3224