#include "bits/stdc++.h"

#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define RREP(i, x, n) for(int i = x; i >= n; i--)
#define rrep(i, n) RREP(i,n,0)
#define pb push_back
#pragma GCC optimize ("-O3")

using namespace std;

// #define DEBUG_IS_VALID

#ifdef DEBUG_IS_VALID
#define DEB 1 
#else
#define DEB 0
#endif
#define DUMPOUT cout
#define dump(...) if(DEB) DUMPOUT<<"  "<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"<<endl<<"    "; if(DEB) dump_func(__VA_ARGS__)
template<typename T1,typename T2>ostream& operator << (ostream& os, pair<T1,T2> p){cout << "(" << p.first << ", " << p.second << ")"; return os;}
template<typename T>ostream& operator << (ostream& os, vector<T>& vec) { os << "{"; for (int i = 0; i<vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : ", "); os << "}"; return os; }
template<typename T>ostream& operator << (ostream& os, set<T>& st){for(auto itr = st.begin(); itr != st.end(); itr++) cout << *itr << (next(itr)!=st.end() ? ", " : ""); cout << "}"; return os;}
template<typename T1,typename T2>ostream& operator << (ostream& os, map<T1,T2> mp){cout << "{"; for(auto itr = mp.begin(); itr != mp.end(); itr++) cout << "(" << (itr->first) << ", " << (itr->second) << ")" << (next(itr)!=mp.end() ? "," : ""); cout << "}"; return os; }

void dump_func(){DUMPOUT << endl;}
template <class Head, class... Tail>void dump_func(Head&& head, Tail&&... tail){ DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...);}
template<class T> inline bool chmax(T& a,T const& b){if(a>=b) return false; a=b; return true;}
template<class T> inline bool chmin(T& a,T const& b){if(a<=b) return false; a=b; return true;}

using ll = long long;
using P = pair<int,int>;
using Pl = pair<ll,ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;

const int mod=1e9+7,INF=1<<29;
const double EPS=1e-12,PI=3.1415926535897932384626;
const ll lmod = 1e9+7,LINF=1LL<<59; 

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  int N,M; cin >> N >> M ;
  using vpl = vector<Pl>;
  using vvpl = vector<vpl>;
  vvpl g(N);
  rep(i,M){
    int a,b,s; cin >> a >> b >> s ;
    a--; b--;
    g[a].pb(Pl(b,s)); g[b].pb(Pl(a,s));
  }
  ll x,ub,lb;
  bool ok;
  vl a(N,-2),b(N);
  function<void(int,ll,ll)> dfs = [&](int u,ll au,ll bu){
    if(a[u]!=-2LL) return;
    a[u] = au;
    b[u] = bu;
    dump(u,au,bu);
    if(au==1LL) chmax(lb,1-bu);
    else chmin(ub,bu-1);
    for(auto p:g[u]){
      ll v,ss; tie(v,ss) = p;
      ll av = au * (-1LL);
      ll bv = ss - bu;
      if(a[v]==-2){
        dfs(int(v),av,bv);
      }else if(a[v]!=av){
        dump(u,v,av,bv,a[v],b[v]);
        ok &= ((b[v]-bv)%2)==0LL;
        ll nx = -(b[v]-bv)/(a[v]-av);
        ok &= ((x==LINF)||(x==nx));
        x = nx;
      }else{
        ok &= (bv==b[v]);
      }
    }
  };
  ll ans = 1LL;
  rep(i,N){
    if(a[i]!=-2) continue;
    x = LINF;
    lb = -LINF;
    ub = LINF;
    ok = true;
    dfs(i,1LL,0LL);
    dump(i,x,lb,ub,ok);
    if(!ok){
      ans = 0LL; break;
    }else if(x!=LINF){
      ok &= (x >= lb) && (x <= ub);
    }else{
      ok &= (ub >= lb);
      ans *= (ub-lb+1);
    }
    if(!ok){
      ans = 0LL; break;
    }
  }
  cout << ans << endl;
  return 0;
}


Measured memory_bytes: 18816