/**
 * Maria Sales Nš 41748 MIEI
 * Ricardo Silva Nš 37798 LEI
 */

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;


public class Main {
	
	private static final int DAYS = 7;

	public static void main(String[] args) throws IOException {
		
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer s;
				
		// Read first line		
		int p = Integer.parseInt(in.readLine());
		
		// Graph construction
		
		Graph graph = new Graph(p);
		
		for(int i = 0; i < p; i++){
			
			s = new StringTokenizer(in.readLine());		
			
			for(int j = 0; j < DAYS; j++){
				char c = (s.nextToken()).charAt(0);
				graph.add(c, i, j);		
				
			}			
		}
		
		// Read next line
		int q = Integer.parseInt(in.readLine());
		
		graph.constructGraph();
		
		// Process tests
		for(int i = 0; i < q; i++){
			
			s = new StringTokenizer(in.readLine());
			
			int res = graph.dijkstra(Integer.parseInt(s.nextToken()),Integer.parseInt(s.nextToken()));
			
			if(res == Integer.MAX_VALUE)
				System.out.println("impossible");
			
			else
				System.out.println(res);
		}

	}


}