#include<bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define mp make_pair
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128;
template<typename T,typename U>
T ceil(T x, U y) {return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>
T floor(T x, U y) {return (x>0?x/y:(x-y+1)/y);}
template<class T,class S>
bool chmax(T &a,const S b) {return (a<b?a=b,1:0);}
template<class T,class S>
bool chmin(T &a,const S b) {return (a>b?a=b,1:0);}
int popcnt(int x) {return __builtin_popcount(x);}
int popcnt(ll x)  {return __builtin_popcountll(x);}
int topbit(int x) {return (x==0?-1:31-__builtin_clz(x));}
int topbit(ll x)  {return (x==0?-1:63-__builtin_clzll(x));}
int lowbit(int x) {return (x==0?-1:__builtin_ctz(x));}
int lowbit(ll x)  {return (x==0?-1:__builtin_ctzll(x));}

#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
typedef pair<int,int> pii; 
typedef vector<int> vi;
typedef vector<pii> vp;
typedef tuple<int,int,int> tiii;
int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=2e5+5;
int n,m,deg[N],del[N],w[N],low[N],dfn[N],tick,in[N],st[N],top;
map<pii,int>ed;
vp e[N],t[N];
queue<int>q;

void dfs(int u,int fa) {
  dfn[u]=low[u]=++tick, in[u]=1, st[++top]=u;
  for(auto [v,id]:e[u]) if(id!=fa) {
    if(!dfn[v]) {
      dfs(v,fa), chmin(low[u],low[v]);
      if(low[v]>=dfn[u]) {
        vi res={u}; bool flag=0; do {
          int x=st[top]; res.eb(x), in[x]=0, flag|=(x==n);
        } while(st[top--]!=v);
        if(flag) for(int x:res) del[x]=1;
      }
    } else if(in[v]) chmin(low[u],dfn[v]);
  }
}

bool work() {
  rep(u,1,n) {
    for(auto [v,w]:e[u]) if(u<v) {
      if(!ed.count(pii(u,v))) ed[pii(u,v)]=w;
      else if(ed[pii(u,v)]!=w) return 0;
      else --deg[u], --deg[v];
    }
  }
  rep(i,1,n) if(deg[i]==2) q.push(i);
  while(!q.empty()) {
    int u=q.front(); q.pop();
    if(del[u]||u==1||u==n) continue; assert(deg[u]==2);
    int x=0,wx=0,y=0,wy=0;
    for(auto [v,w]:e[u]) if(!del[v]) {
      if(!x) x=v, wx=w;
      else y=v, wy=w;
    }
    assert(x), assert(y), del[u]=1;
    if(x>y) swap(x,y);
    if(!ed.count(pii(x,y))) ed[pii(x,y)]=wx+wy;
    else if(ed[pii(x,y)]!=wx+wy) return 1;
    else {
      --deg[x]; if(deg[x]==2&&x!=1) q.push(x);
      --deg[y]; if(deg[y]==2&&y!=1) q.push(y);
    }
  }
  rep(i,2,n-1) if(!del[i]) return 1;
  return 0;
}

signed main() {
  n=read(), m=read();
  rep(i,1,m) {
    int u=read(), v=read(); w[i]=read();
    e[u].eb(v,i);
    e[v].eb(u,i);
  }
  e[1].eb(n,m+1), e[n].eb(1,m+1);
  dfs(1,0);
  rep(i,1,n) del[i]^=1;
  rep(u,1,n) if(!del[u])
    for(auto [v,id]:e[u]) if(!del[v])
      if(w[id]) t[u].eb(v,w[id]), deg[u]++;
  rep(u,1,n) e[u]=t[u];
  printf("%d\n",work());
  return 0;
}