#include #include #define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++) using namespace std; typedef long long int ll; typedef vector VI; typedef vector VL; /* * Union-Find tree * header requirement: vector */ class UnionFind { private: std::vector disj; std::vector rank; public: UnionFind(int n) : disj(n), rank(n) { for (int i = 0; i < n; ++i) { disj[i] = i; rank[i] = 0; } } int root(int x) { if (disj[x] == x) { return x; } return disj[x] = root(disj[x]); } void unite(int x, int y) { x = root(x); y = root(y); if (x == y) { return; } if (rank[x] < rank[y]) { disj[x] = y; } else { disj[y] = x; if (rank[x] == rank[y]) { ++rank[x]; } } } bool is_same_set(int x, int y) { return root(x) == root(y); } }; // Solution in the editoral. int main(void){ int n, m; cin >> n >> m; int conn = n; UnionFind uf(n); REP(i, 0, m) { int a, b, c; cin >> a >> b >> c; a--, b--; if (not uf.is_same_set(a, b)) { uf.unite(a, b); conn--; } } cout << conn << endl; }