#include <bits/stdc++.h>
template <class T>
bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}
using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;
const double EPS = 1e-10;
const double PI = acos(-1.0);
const ll inf = 1LL << 62;
const ll mod = 1000000007LL;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
ll extgcd(ll a, ll b, ll &x, ll &y) {
  x = 1, y = 0;
  ll g = a;
  if (b != 0) g = extgcd(b, a % b, y, x), y -= a / b * x;
  return g;
}
ll ADD(const ll &a, const ll &b, const ll &mod) { return (a + b) % mod; }
ll SUB(const ll &a, const ll &b, const ll &mod) { return (a - b + mod) % mod; }
ll MUL(const ll &a, const ll &b, const ll &mod) { return (1LL * a * b) % mod; }
ll DIV(const ll &a, const ll &b, const ll &mod) {
  ll x, y;
  extgcd(b, mod, x, y);
  return MUL(a, (x + mod) % mod, mod);
}
random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1, 6);
uniform_real_distribution<double> score(0.0, 10.0);
using Edge = tuple<int, int>;
vector<vector<Edge>> G;
vi memo;
bool dfs(int v, int d) {
  if (memo[v] != -1 and memo[v] != d) return false;
  memo[v] = d;
  bool ret = true;
  for (auto &e : G[v]) {
    int nv, dd;
    tie(nv, dd) = e;
    int nd = d + dd;
    ret &= dfs(nv, nd);
    if (not ret) break;
  }
  return ret;
}
int main(void) {
  int n, m;
  cin >> n >> m;
  G = vector<vector<Edge>>(n);
  vi root(n, true);
  for (int loop = (int)(0); loop < (int)(m); ++loop) {
    int l, r, d;
    cin >> l >> r >> d;
    l--, r--;
    G[l].emplace_back(Edge(r, d));
    root[r] = false;
  }
  memo = vi(n, -1);
  bool res = true;
  for (int v = (int)(0); v < (int)(n); ++v) {
    if (not root[v]) continue;
    res &= dfs(v, 0);
    if (not res) break;
  }
  for (int v = (int)(0); v < (int)(n); ++v)
    if (memo[v] == -1) res = false;
  cout << (res ? "Yes" : "No") << endl;
  return 0;
}
