// 懒得写正解了哦哦哦，加个 1->n dis(1,n) 就对了

// Problem: #3806. 「JOI Open 2022」放学路
// Contest: LibreOJ
// URL: https://loj.ac/p/3806
// Memory Limit: 1024 MB
// Time Limit: 2000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

// 私は猫です

#include<bits/stdc++.h>
#define int long long
#define ull unsigned long long
#define ll long long
#define pb push_back
#define mkp make_pair
#define fi first
#define se second
#define inf 1000000000
#define infll 1000000000000000000ll
#define pii pair<int,int>
#define rep(i,a,b,c) for(int i=(a);i<=(b);i+=(c))
#define per(i,a,b,c) for(int i=(a);i>=(b);i-=(c))
#define F(i,a,b) for(int i=a,i##end=b;i<=i##end;i++)
#define dF(i,a,b) for(int i=a,i##end=b;i>=i##end;i--)
#define cmh(sjy) while(sjy--)
#define lowbit(x) (x&(-x))
#define HH printf("\n")
#define eb emplace_back
#define poly vector<int>
#define SZ(x) ((int)x.size())
using namespace std;
template<typename T>inline void chkmax(T &x,const T &y){ x=std::max(x,y); }
template<typename T>inline void chkmin(T &x,const T &y){ x=std::min(x,y); }
const int mod=998244353,maxn=200005;
map<int,ll>mp[maxn];
int n,zsy,deg[maxn],vis[maxn],q[maxn],qL=1,qR=0;
void solve(){
	cin>>n>>zsy;
	F(_,1,zsy){
		int u,v,w; cin>>u>>v>>w;
		if(!mp[u].count(v))mp[u][v]=mp[v][u]=w;
		else if(mp[u][v]!=w)mp[u][v]=-1;
	}
	F(i,1,n)deg[i]=SZ(mp[i]);
	auto upd=[&](int u){ if(u>1&&u<n&&deg[u]<=2)q[++qR]=u; };
	F(i,1,n)upd(i);
	while(qL<=qR){
		const int u=q[qL++];
		if(!deg[u])continue;
		if(vis[u])continue; vis[u]=1;
		if(deg[u]==1){
			const int v=mp[u].begin()->fi;
			mp[v].erase(u),--deg[v],upd(v);
		}else if(deg[u]==2){
			const int v=mp[u].begin()->fi,w=next(mp[u].begin())->fi;
			ll val=(mp[u][v]==-1||mp[u][w]==-1)?-1:mp[u][v]+mp[u][w];
			mp[w].erase(u),mp[v].erase(u),--deg[v],--deg[w];
			if(mp[v].count(w)){
				if(mp[v][w]!=val)mp[v][w]=mp[w][v]=-1;
				upd(v),upd(w);
			}else mp[v][w]=mp[w][v]=val,++deg[v],++deg[w];
		}
	}
	if(mp[1].count(n)&&mp[1][n]!=-1&&SZ(mp[1])==1)cout<<0;
	else cout<<1;
}
signed main(){
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	int zsy=1;
	F(____,1,zsy)solve();
}