import java.util.Scanner;
public class ccc5j3s1_1 {
	//https://dmoj.ca/problem/nccc5j5s3
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		//2D boolean map array
		//LinkedList
		//step

		int N = sc.nextInt(); //how many vertice
		int M = sc.nextInt();
		boolean[][] map = new boolean[N][N];
		int[][] edge = new int[M][2];
		for (int i=0; i<M; i++) {
			int bv = sc.nextInt()-1;
			int ev = sc.nextInt()-1;
			map[bv][ev] = true;
			edge[i][0] = bv;
			edge[i][1] = ev;
		}
	}
}