#pragma GCC target("avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include // #include // #include // #include // using namespace __gnu_pbds; // #include // namespace multiprecisioninteger = boost::multiprecision; // using cint=multiprecisioninteger::cpp_int; using namespace std; using ll=long long; using datas=pair; using ddatas=pair; using tdata=pair; using vec=vector; using mat=vector; using pvec=vector; using pmat=vector; // using llset=tree,rb_tree_tag,tree_order_statistics_node_update>; #define For(i,a,b) for(i=a;i<(ll)b;++i) #define bFor(i,b,a) for(i=b,--i;i>=(ll)a;--i) #define rep(i,N) For(i,0,N) #define rep1(i,N) For(i,1,N) #define brep(i,N) bFor(i,N,0) #define brep1(i,N) bFor(i,N,1) #define all(v) (v).begin(),(v).end() #define allr(v) (v).rbegin(),(v).rend() #define vsort(v) sort(all(v)) #define vrsort(v) sort(allr(v)) #define uniq(v) vsort(v);(v).erase(unique(all(v)),(v).end()) #define endl "\n" #define popcount __builtin_popcountll #define eb emplace_back #define print(x) cout< ostream& operator<<(ostream& os,const pair& p){return os<<"("< ostream& operator<<(ostream& os,const vector& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< ostream& operator<<(ostream& os,const set& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< ostream& operator<<(ostream& os,const map& v){ os<<"{";bool f=false; for(auto& x:v){if(f)os<<",";os< inline bool chmax(T& a,T b){bool x=a inline bool chmin(T& a,T b){bool x=a>b;if(x)a=b;return x;} #ifdef DEBUG void debugg(){cout<void debugg(const T& x,const Args&... args){cout<<" "<size;--i)modncrlistm[i-1]=modncrlistm[i]*i%mod; } return modncrlistp[n]*modncrlistm[r]%mod*modncrlistm[n-r]%mod; } ll modpow(ll a,ll n,ll m=mod){ if(n<0)return 0; ll res=1; while(n>0){ if(n&1)res=res*a%m; a=a*a%m; n>>=1; } return res; } ll gcd(ll a,ll b){if(!b)return abs(a);return (a%b==0)?abs(b):gcd(b,a%b);} ll lcm(ll a,ll b){return a/gcd(a,b)*b;} struct unionfind{ private: int maxN; vector par,treesize; public:unionfind(int N) :maxN(N),par(N),treesize(N,1){ for(int i=0;itreesize[y])swap(x,y); par[x]=y; treesize[y]+=treesize[x]; return true; } bool unite(pair v){ return unite(v.first,v.second); } bool parcheck(int x,int y){ return root(x)==root(y); } bool parcheck(pair v){ return parcheck(v.first,v.second); } int size(int x){ return treesize[root(x)]; } void clear(){ treesize.assign(maxN,1); for(int i=0;i> groups(){ vector> res(maxN); for(int i=0;i> res2; for(vector x:res){ if(x.size())res2.eb(x); } return res2; } }; vector dijkstra(pmat& g,ll first){ priority_queue> que; que.emplace(0,first); vector dist(g.size(),inf); while(!que.empty()){ datas x=que.top();que.pop(); if(!chmin(dist[x.second],x.first))continue; for(auto next:g[x.second]){ if(dist[next.second]>codeforces;while(codeforces--){ ll i,j; cin>>N>>M; vector edge(M); vec za; rep(i,M){ cin>>A>>B>>C; edge[i]=tdata(C,datas(--A,--B)); za.emplace_back(C); } uniq(za); pmat edges(za.size()); for(auto& [a,x]:edge){ edges[lower_bound(all(za),a)-za.begin()].emplace_back(x); } pmat g(N); unionfind dsu(N); brep(i,za.size()){ for(auto [a,b]:edges[i]){ dsu.unite(a,b); g[a].emplace_back(1,b); g[b].emplace_back(1,a); } if(dsu.parcheck(0,N-1)){ cout<