#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <string>
#include <string.h>
using namespace std;
struct node {
    int next;
    double xi;
    node(int a, double b) : next(a), xi(b) {}
};
vector<node> v;
vector<vector<node>> adj(1e5 + 5, v);
vector<int> vis(1e5 + 5, 0);
vector<double> price(1e5 + 5, 0);
bool flag = false;
void dfs(int id) {
    if (flag)
        return;
    for (int i = 0; i < adj[id].size(); i++) {
        node node1 = adj[id][i];
        int next = node1.next;
        if (!vis[id]) {
            if (vis[next]) {
                price[id] = price[next] * node1.xi;
                vis[id] = 1;
            } else {
                price[id] = node1.xi * 1.0;
                price[next] = 1;
                vis[id] = 1;
                vis[next] = 1;
                dfs(next);
            }
        } else {
            if (vis[next]) {
                if (price[next] != 1.0 * price[id] / node1.xi) {
                    flag = true;
                    return;
                }
            } else {
                price[next] = 1.0 * price[id] / node1.xi;
                vis[next] = 1;
                dfs(next);
            }
        }
    }
}

int main() {
    int n, m;

    cin >> n >> m;

    for (int i = 0; i < m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].push_back(node(b, c));
        adj[b].push_back(node(a, 1.0 / c))
    }

    for (int i = 1; i <= n; i++) {
        if (!vis[i]) {
            dfs(i);
        }

        if (flag) {
            break;
        }
    }

    if (flag) {
        cout << "No";
    } else {
        cout << "Yes";
    }
    return 0;
}

/sandbox/1/a.cpp: In function 'int main()':
/sandbox/1/a.cpp:65:40: error: expected ';' before '}' token
         adj[b].push_back(node(a,1.0/c))
                                        ^
                                        ;
     }
     ~