#include <bits/stdc++.h>
#include<vector>
#include <string>
#include<algorithm>
#include <iostream>
#include <queue>
#include<set>
#include<unordered_set>
#include<stack>
#include<cmath>
#include<math.h>
#include<map>
#include<unordered_map>
#include<random>
#include<chrono>
#include <ctime>
using namespace std;
typedef long long ll;
typedef pair<long long, long long> pll;
#define mp make_pair
#define fi(b, c) for(ll i = b; i <= c; i++)
#define fj(b, c) for(ll j = b; j <= c; j++)
#define fk(b, c) for(ll k = b; k <= c; k++)
#define fq(b, c) for(ll q = b; q <= c; q++)
#define fw(b, c) for(ll w = b; w <= c; w++)
#define fim(b, c) for(ll i = b; i >= c; i--)
#define fjm(b, c) for(ll j = b; j >= c; j--)
#define fkm(b, c) for(l k = b; k >= c; k--)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define uniq(a) sort(all(a)); a.erase( unique( a.begin(), a.end() ), a.end() );
// #define sz(a) (ll)(a.size())
#define fs first
#define sd second
#define endl "\n"
#define sz(x) (ll)(x.size())

const ll inf = 1e9 + 123, llinf = 1e18 + 829, ura = 684395049517, mod = 998244353;
void xru() {
    // 9 BOG 4EL
    //  setlocale(LC_ALL, "rus");
    //  freopen(".in", "r", stdin);
    //  freopen(".out", "w", stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
void run() {
    cout << endl;
    system("pause");
}
/////////////////////////////////
ll n, m;
vector<vector<ll>>g, rg;
vector<bool> used;
vector<ll> dp, order;
map<pll, ll> len;
/////////////////////////////////

void dfs(ll v){
    used[v] = true;
    for(ll to: g[v]){
        if(!used[to]) dfs(to);
    }
    order.push_back(v);
}

bool cond(ll v){
    used[v] = true;
    for(ll to: rg[v]){
        if(!used[to]){
            cout << "No";
            return 0;
        }
    }
    return 1;
}

int main() {
    cin >> n >> m;
    g.resize(n);
    rg.resize(n);
    used.resize(n, false);
    dp.resize(n, -1);
    fi(0, m-1){
        ll l, r, d;
        cin >> l >> r >> d;
        // if(l == 3 && r == 1) cout << "BLIN";
        g[l-1].push_back(r-1);
        rg[r-1].push_back(l-1);
        len[{l-1, r-1}] = d;
    }
    // fi(0, n-1){
    //     cout << i+1 << ": ";
    //     for(ll to: g[i]) cout << to+1 << " ";
    //     cout << endl;
    // }
    fi(0, n-1){
        if(!used[i]) dfs(i);
    }
    reverse(all(order));
    fi(0, n-1) used[i] = false;
    fi(0, n-1){
        if(!used[order[i]]){
            if(!cond(order[i])) return 0;
        }
    }
    bool first = true;
    // cout << order.size() << endl;
    for(ll now: order){
        // cout << now + 1 << "-";
        if(first) {
            dp[now] = 0;
            // cout << dp[now] << " ";
            first = false;
            continue;
        }
        for(ll from: rg[now]){
            if(dp[now] == -1){
                dp[now] = dp[from] + len[{from, now}];
            } else if(dp[now] != dp[from] + len[{from, now}]){
                cout << "No";
                return 0;
            }
        }
        if(rg[now].empty()) dp[now] = 0;
        // cout << dp[now] << ";  ";
    }
    cout << "Yes";
}