/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt(); // number of nodes
 
		List<Integer>[] G = new List[n + 1];
		for (int i = 0; i <= n; i++) {
			G[i] = new ArrayList<>();
		}
 
		// read n-1 edges
		for (int i = 1; i < n; i++) {
			int u = sc.nextInt();
			int v = sc.nextInt();
			G[u].add(v);
			G[v].add(u);
		}
 
		int ans = -1;
		for (int i = 1; i <= n; i++) {
			if (G[i].size() == 1) {
				ans = i;
				break;
			}
		}
 
		System.out.println(ans);
	}
}

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NQoxIDIKMSAzCjMgNAozIDUK

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