// see https://github.com/LumaKernel/vimfiles/tree/master/snippets/cp-cpp/temp.snip
/// --- .lumrc Template {{{ ///
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = tuple<ll, ll>;
using P3 = tuple<ll, ll, ll>;
using VI = vector<int>;
using VL = vector<ll>;
using VP = vector<P>;
using VS = vector<string>;

#define omajinai ios::sync_with_stdio(false);cin.tie(0)

#define FOR(i,a,b) for(int i=int(a);i<int(b);++i)
#define FORI(i,a,b) for(int i=int(a);i<=int(b);++i)
#define REP(i,n) FOR(i,0,n)
#define REPI(i,n) FORI(i,0,n)
#define RFOR(i,a,b) for(int i=int(b)-1;i>=int(a);--i)
#define RFORI(i,a,b) for(int i=int(b);i>=int(a);--i)
#define RREP(i,n) RFOR(i,0,n)
#define RREPI(i,n) RFORI(i,0,n)

#define ALL(a) (a).begin(),(a).end()
#define UNIQUE(a) (a).erase(unique(ALL(a)),(a).end())
#define PB push_back
#define EACH(i,c) REP(i,(c).size())
#define REACH(i,c) RREP(i,(c).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort(ALL(c))

#define BR cout<<"\n";

#ifdef DEBUG
#define dump(...) cerr<<"["<<__LINE__<< "] "<<#__VA_ARGS__<<" = "<<make_tuple(__VA_ARGS__)<<"\n";
#else
#define dump(...)
#endif

#define YES(x) cout<<((x)?"YES":"NO")<<"\n";
#define Yes(x) cout<<((x)?"Yes":"No")<<"\n";
#define yes(x) cout<<((x)?"yes":"no")<<"\n";

inline int omajinai_int_in(){omajinai;int n;cin>>n;return n;}
inline ll omajinai_ll_in(){omajinai;ll n;cin>>n;return n;}
inline string omajinai_string_in(){omajinai;string n;cin>>n;return n;}
inline int int_in(){int n;cin>>n;return n;}
inline ll ll_in(){ll n;cin>>n;return n;}
inline string string_in(){string n;cin>>n;return n;}
#define oini omajinai_int_in()
#define oinl omajinai_ll_in()
#define oins omajinai_string_in()
#define ini int_in()
#define inl ll_in()
#define ins string_in()

#define isInside(y,x) (0<=(y)&&(y)<h&&0<=(x)&&(x)<w)

#define fi(x) (get<0>(x))
#define se(x) (get<1>(x))
#define th(x) (get<2>(x))
#define fo(x) (get<3>(x))
#define fif(x) (get<4>(x))

template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '{'; EACH(i, v) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "}";  return o; }

template<int n, class...T> typename enable_if<(n>=sizeof...(T))>::type _ot(ostream &, tuple<T...> const &){}
template<int n, class...T> typename enable_if<(n< sizeof...(T))>::type _ot(ostream & os, tuple<T...> const & t){ os << (n==0?"":", ") << get<n>(t); _ot<n+1>(os, t); }
template<class...T> ostream & operator<<(ostream & os, tuple<T...> const & t){ _ot<0>(os, t); return os; }

template <typename T> inline void smax(T &a, T b) { a = a > b ? a : b; }
template <typename T> inline void smin(T &a, T b) { a = a < b ? a : b; }

constexpr double PI = acos(-1);

/// }}}--- ///

constexpr int INF = 1e9+1;
constexpr ll LINF = 1e18+1;
constexpr int MOD = 1e9+7;

const int N = 1e5;
struct UF {
  int par[N];
  int rk[N];
  UF() {
    REP(i, N) par[i] = i;
    REP(i, N) rk[i] = 1;
  }
  int fd(int x) {
    return par[x]==x ? x : par[x]=fd(par[x]);
  }
  bool same(int x, int y) {
    return fd(x) == fd(y);
  }
  void unite(int x, int y) {
    x = fd(x);
    y = fd(y);
    if(same(x,y)) return;
    par[x]=y;
  }
};

UF uf;
VP g[N];
ll dist[N];
int solve() {
  int n=ini,m=ini;

  REP(i,m){
    int a=ini-1,b=ini-1,c=ini;
    g[a].PB(P(b, c));
    g[b].PB(P(a, -c));
    uf.unite(a,b);
  }

  REP(i, n) dist[i] = LINF;

  VI v;
  REP(i, n) {
    if(i == uf.fd(i)) v.PB(i);
  }

  // dijkstra
  EACH(x, v) {
    priority_queue<P> pq;
    pq.push(P(INF, v[x]));
    ll md=INF, Md=INF;
    while(!pq.empty()) {
      ll di = fi(pq.top()), idx = se(pq.top());
      pq.pop();
      for(P to : g[idx]) {
        int j = fi(to);
        ll ndi = di + se(to);
        if(dist[j]==LINF) {
          dist[j] = ndi;
          smin(md, ndi);
          smax(Md, ndi);
          pq.push(P(ndi, j));
          continue;
        }else if(dist[j] != ndi) {
          return 0;
        }
      }
    }
    if(Md-md>int(1e9+1)) return 0;
  }
  return 1;
}

int main(){
  Yes(solve());
}

//


Measured memory_bytes: 16624