#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma warning(disable : 4996)
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<time.h>
#include<random>
#include<array>


using namespace std;

#define REP(i, n) for(int i = 0;i < n;++i)
#define REPR(i, n) for(int i = n-1;i >= 0;--i)
#define FOR(i, m, n) for(int i = m;i < n;++i)
#define FORR(i, m, n) for(int i = m-1;i >= n;--i)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v,n) reverse(v,v+n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout<<(x)<<'\n'
#define pe(x) cout<<(x)<<" "
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define lb(v,n) lower_bound(v.begin(), v.end(), (n))
#define ub(v,n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i,v.size())cout << v[i] << ((i == v.size() - 1) ? "\n" : " ")
template<typename T1, typename T2> inline void chmin(T1 & a, T2 b) { if (a > b) a = b; }
template<typename T1, typename T2> inline void chmax(T1& a, T2 b) { if (a < b) a = b; }
typedef pair<int, int>P;
typedef array<int, 3> arr3;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 1e9+7; constexpr int MAX = 2000020;
const double pi = acos(-1); constexpr double EPS = 1e-8;
constexpr ll INF = 1e18;
void y(bool cond) {
	if (cond)print("Yes");
	else print("No");
}
long long fac[MAX], finv[MAX], inv[MAX];

typedef int Weight;
struct Edge {
	int src, dst;
	Weight weight;
	Edge(int src, int dst, Weight weight) :
		src(src), dst(dst), weight(weight) { }
};
bool operator < (const Edge &e, const Edge &f) {
	return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!!
	e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

typedef vector<Weight> Array;
typedef vector<Array> Matrix;

#define ALL(x) x.begin(),x.end()

bool visit(const Graph &g, int v, vector<int> &order, vector<int> &color) {
	color[v] = 1;
	for (auto e: g[v]) {
		if (color[e.dst] == 2) continue;
		if (color[e.dst] == 1) return false;
		if (!visit(g, e.dst, order, color)) return false;
	}
	order.push_back(v); color[v] = 2;
	return true;
}
bool topologicalSort(const Graph &g, vector<int> &order) {
	int n = g.size();
	vector<int> color(n);
	REP(u, n) if (!color[u] && !visit(g, u, order, color))
		return false;
	reverse(ALL(order));
	return true;
}
int deg_in[200020];

int dist[200020];
int par[200020];
bool dfs(int n,int pre,int res,Graph &G) {
	if (dist[n] == 0)dist[n] = res;
	else {
		if (dist[n] != res)return false;
		else return true;
	}
	bool ok = true;
	for (auto e : G[n]) {
		int nxt = e.dst;
		if (nxt == pre)continue;
		if (!dfs(nxt, n, res + e.weight, G))return false;
	}
	return true;
}
void solve() {
	int N, M; cin >> N >> M;
	Graph G;
	G.resize(N);
	REP(i, M) {
		int u, v, c; cin >> u >> v >> c;
		u--, v--;
		Edge e = { u,v,c };
		G[u].push_back(e);
		deg_in[v]++;
	}
	vector<int>order;
	if (!topologicalSort(G, order)) {
		print("No"); return;
	}
	else {
		REP(i, N) {
			if (deg_in[i] == 0) {
				if (!dfs(i,i,0,G)) {
					print("No"); return;
				}
			}
		}
		print("Yes");
	}

}


signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q; cin >> q;
	//while (q--)
	solve();
}



Measured memory_bytes: 13436