using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

public class Solution {

    class UnionFind {

        private int count = 0;

        private int[] parent, rank;

        public UnionFind(int n) {

            count = n;

            parent = new int[n];

            rank = new int[n];

            for (int i = 0; i < n; i++) {

                parent[i] = i;

            }

        }

        public int find(int p) {

            while (p != parent[p]) {

                parent[p] = parent[parent[p]];    // path compression by halving

                p = parent[p];

            }

            return p;

        }

        public void union(int p, int q) {

            int rootP = find(p);

            int rootQ = find(q);

            if (rootP == rootQ) return;

            if (rank[rootQ] > rank[rootP]) {

                parent[rootP] = rootQ;

            }

            else {

                parent[rootQ] = rootP;

                if (rank[rootP] == rank[rootQ]) {

                    rank[rootP]++;

                }

            }

            count--;

        }

        public int Count() {

            return count;

        }

    }

    public int findCircleNum(int[][] M) {

        int n = M.Length;

        UnionFind uf = new UnionFind(n);

        for (int i = 0; i < n - 1; i++) {

            for (int j = i + 1; j < n; j++) {

                if (M[i][j] == 1) uf.union(i, j);

            }

        }

        return uf.Count();

    }

}